from the web interface at least, there’s a little picture icon at the bottom of the url box. click that and you can upload your own picture

I’m using the Jerboa app to use and I can definitely see images on posts from my feed. Haven’t seen gifs/video yet but I’ve had this account for an hour

Here’s an example from the all feed:

Unless you mean within comments themselves

Edit: actually I see my image in the comments as well