How is it possible for a graphic on a scrollable area to overlap a frame?

For example, the frame is at the top. A graphic is on the scrollable area under the frame and when you scroll down, the graphic overlaps on the top frame.

Is that a browser mis-function? or what?

Dave

Do you have an example of this, as I don't beleive it is possible. What I think is happening is the image has been chopped up and put together to give the impression that this is happening... that seems to be the case with most I've seen use this effect anyway.

Sorry, I don't have an example....and I've seen it twice.

Here's what happened when I saw it, but not the "how did it happen" part:

I started browser, IE6+, with a start page as the home page. The start page has it's frame at the top of the page. A member's page was loaded. As I scrolled down the page, a graphic on the member's page overlapped the frame.

I really don't think it was intentional, but I was wondering if there was a way to make it happen. It would be an interesting effect that could be used to draw attention to a graphic with link. Maybe a browser mis-function?

Dave