AFAIK, Hivetalk lets you share your screen or tab for video. So you could have one person basically login to netflix/yt/whatever in a tab, and then choose to stream whatever is in that tab w/ audio attached to everybody.
It has a zero-log policy so the only thing the devs are even aware of is the name of the room I think but *nothing* that happens within.
You could think of Cornychat as a twitter spaces style thing with a LOT more customization and with NWC and zapping etc all baked into it. nostr:npub1yx6pjypd4r7qh2gysjhvjd9l2km6hnm4amdnjyjw3467fy05rf0qfp7kza works on Cornychat among heaps of other things nonstop so if you ever have questions, he's your man!
Hivetalk you could think of basically as the Zoom/Discord style video/screen sharing primarily, among a myriad of other features. nostr:npub18pudjhdhhp2v8gxnkttt00um729nv93tuepjda2jrwn3eua5tf5s80a699 the lead dev and inventor, is always around to help too which is great. There's heaps of new features which can also be added if you just throw them into the issues of the github 😄 If the feature is something you're going to use and is useful, the chances are that BITKARROT will implement it.
honestly, I would explore both sites and really have a play around. It's pretty cool with streaming zaps and video conferencing over nostr being a reality now!