Hello, Stormgarde here Just trying to get a picture to come on the forums like seriously i wanna show some knight pictures and so on. Just curious if blizzard will do this type of topic or not since it will make forums more fun and more knight friendly 
There are certain people who can share pictures.
It’s called the Trust Level System. Based on your activity you get certain perks, like posting hyperlinks to trusted sites or straight up embedding pictures.
People start at lvl 0, soon as they enter the forum (Each game’s forum has a separate Trust Level). As they keep on being active, they move to level 1, then 2 and only the most active get to 3, where posting pictures like you desire becomes possible.
You can see more of the requirements (Or, more accurately, get a basic idea of what you need to do) for certain levels on this Hearthstone forum page created by Pachimari. It also has useful info about the stuff you can do with posts on the forums as a whole.
Please do note that the exact values may not be accurate for the Reforged forum. It’s more of a basic idea of what to expect.