Discrepancies in image export

I noticed that when I export an image, I get different images depending on the device used.
For example, my Moto-G (720x1280) exports a JPG of 720x1134 (124824 bytes). My Samsung Note 2 (800x1280) exports a JPG of 800x1219 pixels (142051 bytes).

When scaled to the right dimensions the images are identical.
But why the differing sizes?

It's a screenshot so it depends on the size of your device.

Ah, that explains it. Thanx!