How do I block the 'random image'?

[Meadowlark]

I really don't like the 'random image' that is atop the post block. I can click on the up arrow and it goes away, but only for a moment, then it's back.

I don't see the purpose of it and want it to stop popping up.

[Jon MB]

I am able to toggle the arrow and keep the images hidden, no auto-reappearance for me.
I only see the random images on the forum summary page, not when I'm viewing any of the categories that are listed on that summary, nor when viewing any thread within any of those categories.
Sorry, I can't advise.