It's unclear exactly what the h-e-double-hockey-sticks is going on here - it looks like Bucky is getting recharged like an iPhone, essentially - and it's hard to place where in the film this scene might take place. I'd wager it has something to do with Baron Zemo and his plot machinations, considering the dark and foreboding nature of the shot, and the fact that Bucky doesn't look too happy with being rigged up like that.