I watched the clip in question (or at least the one that's linked on Anvil on Head), and I don't necessarily think a still shot of her with the anvil on her head is noticeably better than the current, but that's me.
I'm temporarily switching it back because 1. we haven't really reached any consensus yet and 2. the formatting on the new picture was wonky.
I personally don't find the anvil picture particularly hilarious on it's own; in context the scene is amusing, but I don't find it particularly funny as a screencap. That said I'm also biased because I put the current pic up there. I'm fine with the anvil one if we choose to switch to it, but I think we can do better.
When I get back from dinner I'll see if I can dig up a better screencap of something.