Why use Snake Case? I would claim it is more common among iOS developers to use lower camel case: viewDisabledBackground
.
I would definitely use an Asset Catalog to organize your images. The nice thing about using a catalog is that the name of the individual images doesn't matter. You just need to slot each image size into the corresponding image well, and give the asset itself an appropriate name. For eligibility you could even consider including spaces when naming images in an Asset Catalog (.xcassets).
The following might be helpful when naming an asset:
Increase Freedom with Folders
Each Folder in an Asset Catalog can be configured to create a name space, allowing you to reuse short names across folders. This gives you a lot of freedom, and will allow you to keep your image names consistent and short. How to set up folders with name spaces, and how to reference the images in your code: https://stackoverflow.com/a/33285214/84682
Use Common Sense
How to best name your assets is obviously a matter of opinion, yet here are some of my common sense guidelines you could consider when naming:
Avoid descriptors that might become outdated; like where or how something is used: topLeftCloseButtonIcon
and LoginCancelButton
are both bad because the button may move or used by something other than login.
Generally use descriptors that makes sense to your entire team: don't call it blueRhombus
if blueSquare
will do.
Append expert descriptors to more familiar terms; chairFancyRococo
.