It’s definitely speedrun sort of technique. Not in “intended mechanic”, though not technically a “glitch”, arguably. It’s just a consequece of how the physics engine works. It’s also referred to as a “bomb impact launch” or “BIL”.

The short version: You jump off of a ledge, go into bullet time by pulling out your bow, lay one bomb, wait until just the right time, lay your other bomb (both in mid air) just so that your bombs are lined up, detonate the first bomb, pushing the second bomb into Link.

While in bullet time, forces are massively multiplied, so the force of the bomb being pushed into Link exerts a massive amount of force, sending Link flying. It’s a really nice trick for locomoting and widely applicable. But definitely takes a good amount of practice to get decent at.

Oh, also, you can see OP doing a windbomb in the above video. And if you search Youtube, you can find a ton of great guides on how to do windbombs.

There’s something newer called “BLSS” (bomb… link… slide… something… I forget what it stands for, lol) or “Bless” that’s probably a little more powerful/fast. I got out of speedrunning before that was discovered, so I never learned how to do it. I’ll probably learn at some point.