What is this metal bar parallel to the frame? I saw this at work the other day and I was completely baffled. This bicycle has an additional, adjustable metal bar that runs parallel to the upper part of the frame, between the seat and the handlebar mounts. It looks like a finished product including labels and whatnot. I didn't see any damage to the frame that I could tell.

Can someone identify this device and its function?
It's used for attaching a child seat similar to this one.



The above site shows a clearer image of the part in question which might be useful to future visitors.