Just wait until someone accidentally burns the shit out of themselves. It actually happens all the time with medical oxygen in hospitals, as in, a controlled environment where oxygen use is expected, and the injuries can be severe, even deadly. Imagine bringing one of these to a BBQ, someone lights the grill too close to you, fwoomp
Consider the shape, size, and price, I also doubt the O2 can in the picture is pressurized anywhere near a proper O2 tank would usually be, which mean…good luck getting relevant amount of oxygen from those cans.
The scuba community affectionately calls similar miniature tanks “three breaths till death.” Because it’s so undersized that you will very quickly run out of air, often without realising it.