You need to be at least jr. member to post images. But you can buy Copper Membership --> https://bitcointalk.org/index.php?topic=2385104.0

That will allow you to post images if you don't rank up as a jr member because you need to have at least 1 merit and 30 activity to become one.

Do you mean as a Jr.member one can post link and image? And is it only copper member that's available to buy? And how much could be the cost?
Learn from the Announcement sections and just look how they've designed it. I'm not quite sure if there's a tutorial for making one but I think there is and someone will post it after me.