Add a way to make mirrors only render specific assets

[Armored-Dragon]

I am essentially asking for mirrors to have a sort of cut out ability. Have a way to make mirrors only render avatars for example. Or have the mirror only specifically render your avatar. This would be helpful for local mirrors, and could also potentially help with performance.

[HifiExperiments]

this might be better suited to something like the existing doppleganger app. this kind of “cutout” isn’t super well suited to the technical implementation of mirrors