Heavy landing?
 

YouTube - XLA6046 - Landing at Skiathos JSI/LGSK

Is this a heavy landing, or normal for short runways?

It's impossible to tell from the video. Dipping the camera may make it seem entirely different than it was.

A hard landing is a defined condition which requires a structural inspection of the airplane...this wasn't very likely to be such a landing. It may very well have been that the person who was filming the approach and landing simply allowed the camera to dip, giving the illusion of a firm landing.

It could have been that the plane was traveling at near stall speeds and proceeded to drop for the final distance to decrease the speed on touchdown

Yay, this is a pilots forum, and you come here to explain how pilots do it when you plainly don't understand? Just leave it for others who do, and learn. You never fly passengers at near stall speeds- maybe one day you will understand how ridiculous that suggestion was!
How can you tell from hand-held camera shake how hard a landing is? Skiathos is a special airport that requires special procedures. Considering nobody swore on touchdown, I would say the landing was just fine. So, no, not a heavy landing. You do not try and do smooth landings on short Greek island airports. But nothing looked unusual there to me.

For Skiathos that landing was excellent! Right place, right attitude. I've filmed from the jumpseat before, looks much worse than it is because you're using a handheld camera.

...FlyingApes guidlines..
 

... if the rubber jungle comes down it's a heavy landing, if the airframe's a write-off it's a crash! ;)

Ohh, and " Yay!!! ", I recommend a trial lesson