The Soviet officer is Semyon Krivoshein, he’s Jewish and not celebrating for multiple reasons. The Nazis occupied Brest when they weren’t supposed to, Krivoshein got there and started negotiating to try to get them to leave. The Nazis were making a propaganda film out of this (which is where the picture comes from) so they wanted the Soviet army to have a parade with them. After an argument Krivoshein agreed that just him and some of his staff would stand there and watch the Nazis parade out of town in exchange for the Nazis leaving Polish prisoners they took in Brest.
Brest was 50% Jewish at this point, in Operation Barbarossa the Soviets defended for 6 days, Jewish Soviet officers were summarily shot by the Nazis, almost the entire Jewish population of Brest died in the Holocaust.
It was authorized last time with Chang’e 5. The problem is it’s not just getting a signature, the bureaucracy takes months and China wants to hand out samples quickly, so last time the US had scientists fill out the application to get rocks before they were authorized to work with them, which risked China wasting time on dead-end applications and having to do even more work to re-assign those samples to someone else if it wasn’t authorized.
China will probably allow US scientists to do that again, but this only works because China agrees to put up with it. They can put a “this research is currently legal” check box on the application and Americans won’t be able to check it until after the deadline.