If you don't like a user's avatar to the point of reporting it, and then we disagree with your report, you always have the option of ignoring a user so you'll personally never see it.
That said, if it gets reported and you're not just trolling, we're fairly likely to remove it I think. We want people to be comfortable as much as we can, without outright denying peoples' ability to post about stuff.
Frankly if it's an avatar it's like... not a big loss ya know? If your avatar made someone uncomfortable I'd say just be decent and find a new one. That's not directed at you personally, just a general statement.