T-molding would give it a nicer finished look. But not bad. 
There is t-moulding installed. Its the white 3/4" (19mm) nintendo type for donkey kong cabinets
I got it from the states from t-moulding.com
You can't tell its t-moulding because i use white melamine mdf.
Bigger pic, not that its any good to you as its still not obvious its t-moulding:

T-molding would give it a nicer finished look. But not bad. 
If that's not T-molding then he has accomplished that professinal look without it. In that case: no need for T-molding!
I could achieve it, as I could use edge banding instead. Its the stuff that sticks to the edge of kitchen cabinets.
You can get it in various colours, from black, white, wood grain, mahogany etc.
Its usually 3/4" in width but you can get it in 1/2" too for narrower sheets.
All you need to do is iron it on with a regular kitchen iron.
This may sound weird but sometimes I dont like t-molding. Its okay on some machines other times its an insult to the machine.
I agree if someone sticks some weird-ass color on it... but you're right, it does sound weird.
It really protects the sides. He's got some clean looking edges there (my guess- painted MDF), but if those sides get banged in to head on, it's going to jack them up.
Just an observation. It's a clean looking machine, but personally I think regular ol' black t-molding would give it a finished arcade look. 
The cab has no paint whatsoever as I use melamine pre-coated mdf.
I then fill in any screw holes with polyester filler, sand it smooth, and then apply the vinyl artwork.
You should check out my cocktail cabinet video, part 3 on my yt channel. I go in-depth on how i finish cabs.
I'm totally enchanted by cabarets with near horizontal monitors, spatially not orientationally (fake word). Vertical ones like this one are nice but don't really do it for me. That said, your execution here looks good. Well done.
You mean horizontal like you'd see on a cocktail cab?
This is my cocktail:

The t-moulding is more obvious to see on that cab.