I believe your picture is rotated 90 degrees, thus it's difficult to assess whats going on in that area because of that, and also because of it's small size.
Are you asking about the door or the hinge pillar?
There is steel (part of the birdcage), fiberglass, and some filler material in that area originally.
Here's what it looks like with the paint and and then with the paint removed. This may help you understand what you're seeing.