I worked several Summers at a Summer retreat. We always had around 30 Japanese students work for maybe six weeks as part of their training.
There would always be two or three beauties. It seemed to me that the really pretty ones tended to be the smaller ones.
Japanese are partial to small cute ones, and as you said, many of their pretty ones are short.
Somebody told me that Japanese hold two different beauty pageants, one for international stage and the other for domestic audience. The former usually favors tall leggy ones, and the latter, smaller cuter ones. I don't know if this is true, but tall leggy ones do not seem as popular as in the rest of world. Even in Japan's neighbors, S. Korea and China, tall leggy ones are popular.