Left Mirror Jiggles

[Vision]

For whatever reason (maybe due to bumping the mirror against a wall while putting the bike away) the black housing(SW ASSY LH HNDL COMP) containing the horn button and the mirror on the top can move front to back a quarter inch or so. Why would this happen, can it be fixed?

[Ruffus]

@Vision, your mirror and this SW assambly are two solitare items, fixed by different screws and bolts.
Mirror with a 6mm bolt (head 10mm) and your electric ASS fixed with 2# screws.
I guess your switch screws are loose. This ASS has usually  a notch which goes into a small hole in your handlebar to be in a certain position.
Find first to position the switch correctely then tighten those 2 #screws.