I think last year the Russians changed from QFE to QNH, and Sheremetyevo is at 600' AMSL. They are also giving up meters for the western feet (for altitude).
So, a crew who isn't very current in COVID conditions, looking at 800' on the altimeter, and reverting to previous experience thinking "That's 800 feet to go, I can still do this" and then getting the shock of becoming visual 200' above the ground.
... and perhaps even thinking "that's 800 meters to go..."??