Yeah, you can definitely think of it like that

I tried browserless.io, it sends every frame as picture from the backend to the browser. I suppose quik will use the same technology?

While supporting IE without any developer work is very impressive, I think quik has some limitions: 1. requres a lot of bandwidth, a place using IE has a high chance don't have a modern internet infrastructure, thus limiting concurrent users. 2. Playing video is basically impossible because intraframe compression is just not efficient enough even on a good network.