The pencil icon for edited comments are far too large on P.SE + Meta. It seems like every other site uses the standard tiny pencil, which works well and is unobtrusive.
I have updated the Edit icon. It is a subtle squiggle line now. I think it fits the whiteboard theme.
I agree, the pencil is massively overstyled (and far too literal) for a whiteboard design, and doesn't look correct. Perhaps an editing mark would be more appropriate -- like a small squiggle indicating "this was edited"