Which two spacecraft are being shown disconnecting here, and what was the connection for?

Question

The new Wall Street Journal video China's Answer to the Aging International Space Station: The Tech Behind Tiangong | WSJ shows what looks like it might be a fuel transfer connection decoupling at 04:14. It's a little scary because after they disconnect the fittings appear to bump and grind a bit, rather than cleanly separate with linear motion.

Question: Which two spacecraft are being shown disconnecting here, and what was the connection for?

"bonus points" for any information on this particular event in the footage; was it sub-optimal? Was anything damaged?

Answer 1

Looks like a demonstration program for robotic refueling that took place on ISS with Dextre in 2013. This was the Robotic Refueling Mission (RMM).

A nasa page with several videos is at https://nexis.gsfc.nasa.gov/rrm_refueling_task-blog.html

So it's not two separate spacecraft. It's Dextre and an experimental device on the ISS.