Book scans: http://archive.wul.waseda.ac.jp/kosho/bunko11/bunko11_a0380/...
Previous discussion: https://news.ycombinator.com/item?id=18430610
AIC is having a great run with prints lately. Before this they did a whole exhibit on Japanese mass produced prints, using Hokusai's "Great Wave off Kanagawa" and its variants as the leading example. 
But I think compared to Asians, white people objectively do have bigger noses, so they're not wrong.
Well, compared to Japanese faces, they certainly do.
How about "How the Japanese imagined Westerners in 19-Century prints"?
Also, why liberal arts in scare quotes? Of course the term comes from liberal arts; social sciences come under that umbrella and have done for years. If it's a politically-charged term, then just call it humanities.
A "particular but difficult-to-illustrate concept"?
Westerners (in particular) or foreigners (in general) both perfectly capture what the Japanese where depicting, without the baggage and obscurantism of "Others".
And yes, the concept of the Other is not easy to illustrate because it has less to do with the parties involved and more of their understanding of each other, the lenses through which these preconceptions are analysed still being debated to this day. It's helpful that there is a word, even if it's merely shorthand, to describe this concisely.
There is nothing black and white about the Other but equally this being a story simple of Western and Japanese is not as night and day as you claim.