I wasn't sure what you were referring to in your original post. In the picture below, I've circled in purple what alm001 is referring to. When I read your original post, I thought you were referring to what I've circled in red. I think what is circled in red is just a reflection of the latch below on the jamb, and due to the lighting that area looks deeper than the silver car, but in actuality both door jambs are the same.
