Man...I remember the first time seeing this with Mai-chan and legitimately laughing out loud. I was caught off guard at that rope smacking her in the face
Did Danbooru just recently add the ability to post webms embedded with sound? I know some other -booru sites like Gelbooru have had it for a while.
As far as I know it came along with the ability to upload MP4s in the release of v2.92.0, as Twitter started using them instead of GIFs. I'm often wrong about these things, though.