I don't think so. I would say it's a tank soldier's head ( possible the commander ) wearing headphones. Also there is the cupola cover and a kind of mount for something IMHO.
Yep, the 'bracket' on the left of the cupola is the mount for the AA mg, which, if needed, was removed from the hull position and mounted on the arm, which could elevate, and traverse around the ring mounted around the cupola periphery.
... the bulk of the Japanese tanks were infantry tanks with guns that were designed to fire high explosive rounds so they were useless against Soviet tanks and their high velocity rounds. The infantry took out Soviet tanks with gasoline bottles, grenades and satchel charges .... Soviet tanks were running on gasoline engines .... Nomonhan changed that .... diesel afterwards, along with latches on the inside of hatch covers and re-designed engine compartment gratings. These changes were implemented between June 1938 and August 1938 .... very responsive industry.
.... this was Nomonhan ... 2 summers later ... only one of the players had the chance to 'rehearse' before, but even so, it was the Eastern and Mongolian troops that Zhukov was able to safely detach from the East and throw in at Moscow that saved the Soviet Union from losing Moscow.
Combined arms in action on steppe .....