Re: real-time wireless video transfer between the ISS and a visiting spacecraft.
If you're talking about the SpaceX Demo-1 mission, it may be that both feeds were visible to the ground, but only to each via ground relay through the TDRS satellites, which isn't practical for the Moon or Mars.
I assume this will be more like an approaching spacecraft automatically becoming part of the station's network so it can be controlled remotely and broadcast its progress so the station's computer or occupants can judge whether they think it's safe to proceed without the go/no-go from Earth-based mission control that happens on the ISS.
