I have the Soviet coat of arms as my profile picture. It is the version from before 1956 so it also has the Karelo-Finnish SSR.

Personally, nearly all my profile pictures are just fictional character i like + bi flag and/or hammer and sickle in the background so idk much in the way of “professional” pfp’s lol but in that scenario I’d probably go with some sort of historical photo of a leftist figure, preferably someone less recognizable to your average lib depending on how “professional” the environment is. As much as i love ol’ joe he was absolutely correct in saying a pile of rubbish would be heaped apon his grave. So pick someone deemed more “sensible”.

When I first got to this place, I had a picture of Chad Jinping:

But then some other people had the same picture, so that lead to some confusion.

I then chose Thomas Sankara as a pfp. No specific reason other than him being based and his smile resembling my own smile in real life.

“Solemn Oath”, Red Army recruitment poster from 1918. Translation here.