Sometimes people post links to screenshots as an alternative to linking directly to their own site-- mainly with HTML or CSS questions. But the screenshot may not stick around forever. ("Why did I put this in my photobucket album? It's nonsense!") So then you're no better off than if they had posted a link to the offending page.
Now, if the WebmasterWorld forums had a mechanism for hosting screenshots for those subforums that need them, then you'd have something stable and permanent.
This would be helpful so we can follow threads via email
Y'know, this forum could probably save a lot of bother just by swiping code from php/bb. It's open source isn't it? No point in reinventing the wheel... (This particular feature-- including post content in e-mail notifications-- is one of the few from bb2 that wasn't incorporated into the core of bb3. It's still an add-on.)