Sometimes when summoning a companion, it simply doesn’t appear and disappears from your inventory, The companion stays like this until you decide to leave and join the game, There is no way to show this in an image because it is not possible.
Did you try to go to a companion station if that happened? Usually it should disappear if you open the station and reappear if you leave the station.
Try for example to add an armor or to change the weapon and leave the station.
I have no experiences with this issue as my companion always is in use.