I don't see anything particularly American about those kitchens, but then again I might not. It's out of fashion these days to have washers and dryers in the kitchen, but that was common here when I was growing up. The basement was the most common place for them, but people lacking finished basements usually had them in the kitchen. (There was, in fact, a washer sold in the 50s which would wash both clothes and dishes, although it did neither job very well).

I was speculating along the lines of appliances too. That was just after the post-war austerity had ended, so 'American' probably still equated to 'extravagent' in a lot of peoples' minds.