Can you spay a cat from side? pic included

So one of my friend spayed from a vet and the vet spayed the cat from side, I mean he made the incisionfrom side.

I think that's very common in Europe.

The vet said , if you spay from side the pain will be less so he spayed from side. is that true or even possible ? :s

I thought the way they spay in Europe was through a small incision on the inside of the upper thigh. Never seen this through the side approach. I'm guessing it would be less painful because they don't have to cut through the diaphragm muscles like they do on a belly spay?