I came across this video which says it’s about hand position in blocking. It brings up something I’ve seen a lot of in the men’s game, which is guys basically throwing their hands/arms across the net when they block. You can see it quite clearly in the second clip in the reel. It’s the same thing I see all the time watching men’s volleyball, and it’s had me wondering for a while what these guys think they’re accomplishing.
To make analysis easier, here is a frame-by-frame progression of the second block. Here’s his position at hand contact. It’s hard to tell, but there’s probably some penetration. His shoulders look square to the net and his arms look pretty even as well, though he does have his left hand turned in.

Here’s when the ball contacts his arm. Slightly more penetration than where he started, but his shoulders appear basically still square and arms level.

Here the ball is clearly off the block. His arms are continuing to press and still look pretty much even.

Now we’re starting to see the left arm press/turn more.

And finally he’s fully pressed over with more clear difference between the two arms. Here is where the “lean” comes in. Notice how his shoulder is closer to the antenna.

My contention here is that all that he says he’s doing about leaning or whatever happens after the actual block. As a result, it cannot influence the ball. The block has already happened.
The initial block from the reel is a different story. Here you can see he’s clearly got the “lean” he talks about.

I see two key differences between the reps. The biggest is time. In the first one he’s blocking a back row attack, so has more time to get his block positioned before the ball arrives. Second, the first block has less of the “throwing” of the hands the second clip shows.
The bottom line is, when evaluating blocking technique, we need to look at what the block looks like when the ball arrives, not what it looks like afterward.
For more on blocking, have a look at Volleyball Blocking Strategy: How to Build a Block-Defense System and my review of a block penetration drill.
