The game gives the camera something to do
Plain video chat with a stranger runs out of things to say in about ten seconds. omequiz puts a quiz in the middle, so the camera carries the reactions — the groan when someone misses an easy one, the grin when they steal the lead on the last question — while the questions carry the evening. You are not staring at each other with nothing to do; you are playing a game together and happen to be able to see each other.
That is the whole difference from open random video chat. There is no "next stranger" button and no empty screen to fill. The game is the reason to be there, and the camera is a bonus on top.
Off by default, always optional
Camera and microphone start switched off and turn on only when you turn them on. They apply per room and per session, and you can switch them off again in the middle of a game without leaving. A quiz plays exactly the same with text only, so nobody is ever obliged to be on screen to take part.
If you would rather not show your room, background effects let you blur or replace what is behind you. And turning a camera off mid-game is treated as normal, not a snub — that norm is part of how the feature is meant to be used.
Moderated, because faces raise the stakes
Video between people who have just met needs real moderation, and this is where a lot of that work goes. Camera streams and uploaded images run through automated checks, any player can report another with one click mid-game, and reports land in a moderation queue backed by warnings and bans. Playing requires an account, so behaviour is tied to an identity rather than being anonymous.
The full detail of what is checked and what happens after a report is on the safety page. The short version: the feature exists because the game makes video worth having, and it is moderated because video with strangers is not something to leave unmoderated.