Many bad things actually. First, the keyboard and mouse stand will just fall over, full stop. It wouldn't even stand on it's own. The sharp edges on the glass inside where you sit will be a pain, you'll knock your head against them many times when you crawl under your desk. The glass "roof" is just weird. It will make you feel uncomfortable when you sit at this table, it will feel claustrophobic. Also the fact that there are steel legs on both levels will make you feel like you're sitting in a box. Basically, you might just as well put your PC in a cupboard and sit at it with open doors. Also, I would assume you can buy these types of legs at a home depot or smth, but doing cable management through them will simply be a nightmare and less than not practical. Quite a bad design, really bad actually.
Sorry for all the bad stuff. Just expressing my thoughts. Try something less complicated, something very simple. The simple things usually turn out to be the best. + a simple table will make everything look tidy, something like this would make it look cluttered.