ML's bat is moving downwards slightly this adds backspin, he also 'shakes' his wrist at impact which adds some more spin.
Okay, that's really hard to see. I was also very impressed with fang bo serves .
https://youtu.be/2NFvEqTxt0E
For example first 2 serves are intresting. Second one is quite easy to tell that's with topspin but first one is very tricky. I don't even see a movement that could create a backspin.
It's not a side under serve, but a float/no-spin serve. Joshida's flick clips the net probably because he tried to flick the ball aggressively while keeping the return as low as possible and did not quite compensate for the lack of spin on the float serve.
I think his serve has some spin, maybe little but it is not a float serve. What about Fang bo serve?
Looks like no spin serve to me and the service return was stuck with two shots, at first a drop shot/push long (which would go high) and later changed to a flick, but was late, so it hit the net
Intresting