Ah, is that why... I noticed this too but assumed it was due to some communist ideal of gender equality leading to more women tradespeople, wishful thinking I guess
The poorer the country, the more women work in traditionally male fields. In Bolivia and in Peru, I was surprised to see many women working in construction and driving taxis.
If not for the war or other legitimate reasons I'd assume a preponderance of one demographic doing a specific job as likely a bad thing. I'm surprised it'd be wishful thinking.
I was expecting to find out that lots of men killed in the war led to many more women working after the war, and that's what could be interpreted/guessed from these pictures.
But looking at wikipedia, it's complicated. A lot of different estimates of deaths. I think a lot more men died in ww2 in the Soviet military, from Wikipedia, about 20 million men (see total war deaths by age group table) and 6 million women. The official counts of the dead were supposed to have underreported deaths by a lot.
Looking at different estimates in wiki, about 10 million military dead and almost 20 million civilian dead.
https://en.wikipedia.org/wiki/Rosie_the_Riveter