No? Why would they need to be in different machines? You can stream from one GPU to another, whether they're in the same machine or not. One GPU may be a cheap little one built into your motherboard. You probably already have it anyway!
And even if you did need two machines... again that's how gaming streaming services work. Cheap end-user machines or iPad or just TV, and then a gaming system streaming video output somewhere else.
Thats not really called "streaming". So given that somewhere in this thread there was a youtube link on how to do that, which required testmode in Windows - it's still not practical.
The data would literally be streamed along a bus from one storage to another. The name ‘streaming’ literally appears in some APIs you’d use to do it!
That's exactly what streaming means as a technical term:
Examples:
https://wiki.libsdl.org/SDL_TextureAccess
Make up your mind. If I counter your "video streaming" argument, you can't come with "but I meant streaming on the same device" without even mentioning either a technology, or the most important thing there (the frame buffer). Now you want streaming to mean something that is used in game engines. How those 3 links help in making the mining card usable is for you to proof.