It didn’t pop up for me.
No info, no message (in a world where I already finished all missions).
I looked for a mission icon on the map. Nothing to see in the log so far. I saw the red icon and went to vesslan. The mission started with picking up the letter at the station.
Same here , there was nothing on launching new session, letter started it 
It didn’t popup for me, but i had read from where it started (while it downloaded)
I were in a World where i had Cleared all of Archipelago and majority of Farmlands and South coast.
So i looked in the logs and after moment i noticed a Main Missions i didn’t recognize called “Making Friends” but no map icons.
Yes, that’s what I meant, I was led to the Vapenkussan at the back entrance of Vesslan. There I picked up the letter. In my memory the orange mission marker was there before I picked up the letter. I will play the mission again and see what exactly happened.
I was however, led to that vapenkussun with the still unequipped Companion Station. To me the popup notifying me that I got a new mission in my missions log, is the start. ( is a bit confusing)
Edit: The popup was a procedural mission
Ok I restarted the mission. I got a popup, but that was a procedural mission. That was why I looked in the missions log. There the Mission “Making Friends” was on the top of the list, unactivated. When I activated the Orange mission waypoints were on the map. I was at Himfjäll, and this time I noticed the orange waypoint at the Björntunet Hotel Companion Station, I didn’t noticed it the first time.
So I’m guessing, depending where you are, you can find the Starting letter at every Companion Station nearby. To check this further, before doing the mission I took some more pictures of Companion Station locations. I took more pictures, but these six should be more than sufficient. Click pics for larger view.
So we know now that you can start the “Making Friends” mission at every Companion Station you like.
In my original first run I did not take the letter at Björntunet, because I had not noticed the waypoints there. Instead I looked on the map searching for a orange waypoint, and lo and behold there was a orange waypoint near Vesslan. So I travelled there. I should have looked more thoroughly. 
I also checked if the mission was already in the missions log when I logged in after the Companion Update, and it was (in a new world Ditto. When I activated the mission in the log I got a orange waypoint to the a Companion station with a starting letter nearest to my location, but you could travel to other stations and find a start letter there.
That all folks… 
Okay, over 150 postings in this thread, and we have discussed paintwork, play fetch, petting, how to activate the “pup” and what not. All cool and dandy - I mean, I like a nice paintjob and when somebody plays with my stick just as much as the next guy. But it seems to me, that only @lithilya had the guts to question the whole concept when stating:
I like the idea of this Ally. Not as an obediant “pup” but more like an equal joining the fight. Because, to me, the real question is: Who is controlling this machine? And to quote @Gysbert:
Why is it heartbreaking, when a machine breaks down? Who’s the subject of this suffering? Who dies?
Deep down in a bunker under Ôstertörns mountains a swedish teenage girl with deep blue eyes, fair blond hair, and a smile that can melt hardened glass is kept in stasis by FNIX, her brain hooked up to control a runner. Somehow, the resistance managed to turn this runner to our advantage without FNIX being aware of this deception. If FNIX knew, she would be “decomissioned” instantly. Did she in her endless nightmare volunteer to join us, or did we just transfer her slavery to our advantage? Do we just treat her as a dog, petting her and letting her fetch our stick for our amusement? Do we even care, when she takes a beating or … die? Are we any better that FNIX, treating this young girl as a tool for our cause and entertainment?
Were we not supposed to be the good guys? No “pup” for me unless someone can provide a solid and consistent explanation that does not imply abuse.
I just would have said that it’s just an AI.
If the machines really are controlled by humen, the resistance maybe managed to cut the connection and replace it by a simple and local AI.
Either way, I don’t believe that the humen are needed to control the machines.
I could think of them being used as knowledge-database to feed the AI, but not as control-units.
I merely copied the information from Twitter. And, to make sure it’s no longer a source of irritation, I’ve removed that Quote. Hope you are OK.
Sorry, @Gysbert , I’m not making you responsible for this statement 
But you are an authority on game lore and you are conveying new information about the game 
I simply find this discussion far, more interesting than whether or not you can fit a Kill-o-Zap gun on the “pup” 
That’s perfectly ok. Good controversy is usually more interesting than pink sweet bubblegum. So what’s on your mind? Edit: Look at the time…I have to go, it’s movie time for me. 
Well, is my assumption correct or can someone offer another plausible explanation that doesn’t involve human mind control and still would fall within the reach of the technology of Ōstertōrn in the late Eighties?
Do we still have a consistent story and therefore consider the implications of the “pup”, or should we stop worrying about the story and just play the game for what it is … a game 
Perhaps, but I find it hard to believe that a non-biologically based AI would be up for the job back then. But that raises another question: how are the Russian machines controlled? Admittedly, it is much easier to construct s regulation system for a control unit balancing on a ball, than a bi-pedal construction like the hunter, but still … Anyway, that might be another discussion.
I was just about to ask exactly the same question.
Nowadays of course it’s “no problem”. At least it’s already reality. But I’d say that is nothing to discuss about. It’s s game.
And there aren’t just bi-pedal (hunter, tank) and ball-balancing (lynx) units. There are 4-legged machines (harvester, wolf, runner) as well as flying machines (seeker, firebird).
This is Motor Claw.
…he’s allright! 
Here’s a photo of me and him waiting for the next island DLC, and maybe Half Life 3 while we’re at it. 
With stories there are always a myriad of opinions. But I guess, with a nimble mind like you have, you should still be able to follow the general path of the story even if there are some information gaps.
We know that the Resistance has seized the opportunity to utilize secret materials scattered over Östertörn. They are using these materials to construct a machine that can block FNIX’s radio signals and have it implemented with a new Resistance protocol to help in the fight.
Although the Resistance has discovered information about Project “Blue Paw,” many details remain unknown. Nevertheless, the Resistance now understands that the machines are controlled and coordinated through radio signals. By jamming these signals, they can prevent FNIX from sending machines to perform unprogrammed tasks. The next crucial step may involve completely disabling the machines, but that piece of the story we have yet to find…
I suspect, they are not controlled, but work independently via a programmed protocol. We know that this went horribly wrong (maybe due to foul play from the side of Bolshakov) when the Soviet machines attacked humans, which was not what they were programmed to do. They were there to fight the FNIX’s machines only. The Information about malfunctioning of Soviet machines has real-gameworld consequences, since many a player understandably concluded that the Soviets were hostilely invading Östertörn.
Thanks, @Gysbert , that was interesting and informative. Seems like the story remains intact. I’m still curious how the “pup” is controlled though, as it appears to have a personality.
Without the radio signal it uses the scavenged HD you have to seek out for it’s instructions. So I’d have to say it’s got an AI… hopefully better then the ones the Soviet bots are running or our companions may have a similar issue later on…
I don’t think that it’s controlled at least not remotely, but it most likely has an advanced protocol running. It can only do certain things. For instance it does not know it could easily jump over a 60 cm stone wall. It still has a long way to go. 
Edit: Maybe it’s get imprinted to the person who builds it and does the configuration.
But we found a Blank Disk Drive. There were no instructions on that. That’s why I assumed that the Resistance wrote a set of instruction for Goo-D bo1 to follow, themselves.
