An image is not fair use. It's just an image. Fair use is a test of how someone uses expression copied from someone else's existing work. Publishing the output

An image is not fair use. It's just an image. Fair use is a test of how someone uses expression copied from someone else's existing work. Publishing the output to report on problematic prompt patterns (as in the Twitter post by Reid Southen @Rahll) is probably fair use. (Can't know for sure unless a court rules on the specific case in question.) Publishing the output while saying "you should try this for a free poster" is infringement.