As others have said, it is supposed to flip over as the slides moves in or out, but it really doesn't make any difference as long as the edge is in contact with the slide wall. Besides, what you see in the photo is just a wiper, designed to clean off debris and water as the slide moves in/out. The actual weather seal is on the flange where the inside or outside slide wall presses a D-shape rubber seal against the RV sidewall.
The potential problem is a half-turned wiper rubber, which may leave a gap where the edge turns over. Not a big deal, though.
Former owner of 2004 American Tradition and several other RVs
Home is in the Ocala Nat'l Forest near Ocala, FL
Summers in Black Mountain, NC