This seems to me to be a test run, done in a low security locale.
From the damage pattern the device was quite close to the skin, but not enough yield to do more damage. Probably it was also triggered too early. If it had been done with a greater cabin pressure difference, it could have possibly caused more damage.
If i were the relevant security services, i would be looking closely at what happened here, and what was used, as the real run may be closer to home.
Pink smear down the outside is clearly trace of an unlucky person (if device planted) or the asshat who was carrying it.