>>50317116Made the most sense to me but apparently it's a clasp or fastener at the bottom of the satchel.
I don't get what the lines on top of the right graphic are supposed to be then, though. A seam that's normally covered by the flap? The strap was drawn pretty short and the "seam" seems very close to the edges - it looks like it should be showing on the bottom part of the satchel. Maybe it does in high res?
