Unify images icon family
Right now there's a few different things going on with the Photos app, the image mimetype, and the photos folder. I think ideally we want to have a stronger connection here maybe sharing a single dominant color, something that translates well into symbolic for the folder and it needs to scale really well for the sidebar icon.
Maybe something in this direction:

@danrabbit
It is possible to do what I suggested above (not necessarily exactly the same, but the direction) as a symbolic icon,
And the photo app, we can make a logo like this:
This is a direction that allows for different levels of detail. But the relationship between them was still maintained.
And, this is an almost universal form for 'photos', that even did an experiment on Google photos:
