FWIW, I've seen that rather odd gigantic symbol (which I gather signifies a "broken link" or "image missing"?) on a number of different threads. However it's not familiar (I've only seen it here) and not particularly meaningful.
It might be helpful if it could (at some point) be replaced with something more recognizable - or just some text that explains the nature of the problem ("image not found" or whatever).
In the scheme of things, it's not a huge deal, and I'm sure we can live with it for now.
New people onboarding will be apt to be a bit puzzled by it (as I was) until they catch on that it's a placeholder for a broken image link. So --- something to put further down on the "to do" list, maybe.