It certainly does appeart that this was an oxygen bottle by the placement.  With the high pressure inside those bottles and the differential in pressure across the skin of the pressure vessel, it doesn’t take much to create a hole.

A close-up of the damage.

Closer view yet.  The damage to the electrical wiring is apparent.

These look like some sort of oxygen system blow-out valves, but I’m not certain.  Anyone with more information on this?

The explosion also did damage to the passenger door above the bottle.  Don’t see the damage?

How about now?  Take a look at that last picture and you’ll see where the reinforced skin around the door was compromised.

A view inside the cabin which seems to be directly above the explosion.   There was significant damage to the interior of the aircraft, none of which seemed to be structural.