My pic wont post

Convert the image to jpg aka jpeg. It's pretty universal. You may or may not have some loss in quality depending on the original format.
Most image editors allow you to save a photo in different formats.

Who says🤨 Might be a glitch,kinda common here..if you see it,no corruption

Rats

What's the file format?

Technology. Never works when you want it to. 😔