I've done ~20 prompts so far and not had one be rejected so far. What sort of things are you asking it to do? I've tried things like changing clothing and accessories on people.
I just went back to the chat and asked it to remove the glasses and it worked. Asking it to remove the shirt also succeeded, although a) this is a head and shoulders photo so nothing NSFW, and b) it didn't do a great job of guessing what my shoulders look like.