Sorry that this was late. I've been feeling a little under the weather.
As for how this goes, you post a work of yours, finished or WIP (aka work in process, for those who are new to abbreviations), and then others give you critiques on your work. I do not mind if you post the occasional non-HM picture or piece of writing, but keep in mind that, though there are some, not all of us here are writers or do art outside of HeroMachine. All I ask is that you only post pictures that are your own design and not any that copyrighted or based off of copyrighted characters. As for pieces of writing, I’m not sure about whether fan fiction is allowed, but for right now, just in case, don’t post fan fiction either.
Also, again, if you post a work, it is highly recommended that you also give someone else a critique.