According to this comment https://github.com/WebKit/standards-positions/issues/41#issuecomment-2107438556, Spotify is using document pip. I haven't verified the situation on Firefox or if there's breakage. That's why I didn't add any webcompat:* keywords.

I file this for the tracking purpose for now - when we are close to shipping the Document pip, we should verify.