Boeing 737 blown across tarmac by strong winds- GIF

[Duke_of_URL]

Yep, they've been designed to do that, fly that is, even on terra firma, given sufficient wind speed, without additional restraints.

Notice the nose wheel was not pointed straight ahead, brakes applied, wheels chocked. Lack of those "checklist" items was enough to provide initial momentum.
It's possible this "tail" was undergoing "minor" maintenance prior to movement (back?) to the gate, but it still doesn't justify the lack of wheel chocks, or no parking brake.

Replacement of that leading edge, which hit the stairs, is pricey and time consuming, but it also appears that the nose hit the winglet of the other, properly parked, jet. This added damage to the Radome and Weather Radar Antenna/Drive. The stationary jet needs, at minimum, Winglet replacement, and, at most, entire wing replacement. These aren't unusual repairs, given parked aircraft are hit all too often by de-icing/fuel/food trucks.

Pro: Hey, wanna know how to make a 'little bit' of money in aviation?
Amateur: Sure! How?
Pro: Simple, start out with a whole lot of money.