The oxy cylinder we think we are seeing is lying flat horizontally actually on top of the "frame" section you guys are discussing. Go to the absolute lower left corner of the torn skin opening and you can just barely make it out (under Peter's added word "frame".)
I'm not sure if there isn't actually a second frame (above & below my word "frame") that looks like it has been sliced off at the same horizontal position and pushed 90° just like the frame next to it... same chicken or egg question though...
How much force would be required to slice through 2 frames like that though - and the edges appear to be cleanly sliced through...