There’s this strange bug that occurs when uploading an image to roblox, your image’s preview picture will be heavily distorted/noised as shown below:
This bug is very common for very low resolution images.
Thankfully, this bug doesn’t affect the actual asset when placed in the roblox engine.
As far as I know, this bug has been happening for a few years. (I don’t know exactly how long, but it sure has been a thing since early 2018)
Reproducing the bug is pretty simple. All you have to do is upload a low resolution image to roblox. And then if you go to the image in the studio toolbox or the roblox website, the image may get bugged.