it's likely you are referencing to the "thing" category! many people ask questions or share things under different "things" and many people put an "answer" in said questions! when you put an answer you can add whatever image you want with whatever caption and content! you can find the "thing" category in your account homepage. i hope this helps!
If I’m not wrong when u see “people are posting” on the bottom right side on the last reply it says “more>>”. Click on that and then scroll to the bottom and click on the orange bar. Then it tells u how to do it from there
like the things on the side where theres a title nd u can reply to it not like this "ask a question" thing the "People are posting things" thing how do u post things