As a new user to the forum (trust level 0), you can only post a single image. This restriction is quite useless in its current state.
It creates a lot of friction for both the poster and the people trying to help. When the poster can’t explain their issue thoroughly, due to not being able to upload all of their screenshots, unnecessary replies has to be made just to clarify the question. It also causes confusion when the poster don’t know why their images won’t show.
The restriction is also easy to circumvent by creating more replies. Some new users figure this out, but this is an unwanted side effect of the restriction, as it effectively makes it useless. It’s better to have all images collected in one post.