FeKa and Anonymous, the abbreviated kb file size is meaningless, since it's an approximation anyway. This is nowhere near as cool as http://modarchive.org/module.php?46466 , a 1999 new year's tune which is 1999 bytes :D Anyone can make their canvas size 999x999.
One out of every 10 images has that property, though. The odds are 10% - that's pretty high, don't you think?
I doubt it was intentional, since how would the artist know that danbooru happens to round their filesizes to the nearest 100 KB? It's just a coincidence :) And not a particularly odd one either.
