You have to use an image hosting site such as imgur.com (that's the one I use). It's really easy, just go there and upload an image, you don't even need an account. Once you upload an image it gives you the forum code to insert the image into a post. I have an account because it's free and that way it keeps all the images I've ever uploaded.
You can't upload images directly to Bluelight, we tried allowing that for a while but it was making our server space grow really fast.
I was very close to voting for you if it's any consolation. Tbf they didn't vote for the winner of the previous two contests so they must not know art when they see it.