I agree that most screenshots of code are pure lazyness. And especially because putting stuff in working code will force you to think about what you've done, it is good to enforce a rule like: 'avoid posting screenshots of code'.
But, I can think of a good reason to add screenshots and sometimes even omit the code itself. IDE's like Android Studio can display lots of debug info right next to the code, which will often show that the problem you have is not because of bad input values. Then, the code itself may just be disturbing extra and the screenshot may be much more useful. Moreover, in a screenshot you can grab multiple parts of multiple windows, which can give a good overview.
I'd say it all depends on whether the poster has thought about how to best present the issue, and decided knowingly to (also) post the screenshot(s).
