These yokohama-e are from Yokohama, which at the time was a tiny little seaport which was one of the few ports open where foreigners were allowed to land... and so these yokohama-e prints depict images of westerners... images that the native Japanese were curious about because everyone wanted to see what the Americans looked like.
Truthfully the art is bare basic, and aside from the length of the noses, and the color of the skin, the figures look Japanese... or as Japanese as any ukiyo-e figure.
The thing with these yokohama-e images is the clothing...which to the average Japanese of the day would have found to be quite different, and weird.
I bet the Japanese would find it intriguing to know WHY the American in the image above has a cane, when he obviously doesn't need one (an assumption on my part), as the can was used, in that era as a walking stick... an adornment to one's attire.
I wonder, however, if the Japanese would look at this yokohama-e and think... except for the clothing and nose and skin/hair color... these Americans look and act just like us?
That was one of those thoughts I had prior to going to Japan and was able to maintain even after leaving Japan.
It's just people.
As for the print above... it's called 'Amerikajin no zu' (portrait of Americans) and is by artist Utagawa Yoshitora (歌川 芳虎). Utakagawa Yoshitora was a student of Utagawa Kuniyoshi... an ukiyo-e artist of whom I know, having a few of his prints. It's why the Americans look similar in art style to the Japanese in print.
PS: Thanks to Matthew for the lead on these yokohama-e woodcut prints.
PPS: As for my headline... it's tongue in cheek... seeing as how I think people look the same basically.