[Blue Jays]

Whether it is chest-height or at floor-level when it detonates...nobody wishes to be near such a horrible device wielded by terrorists.
Authors of articles should not get too wrapped-up in details of the hardware. It is radicalized Islamic jihadists who wish us grievously injured or dead.

[USNBandit]

For an airport, their choice of device makes sense. Why wear a suicide vest that might stand out when you can push a cart around, just like everybody else, and pack more explosives in it.