Perhaps it’s more of a ‘meh’ look than just being outright unimpressed at being on the cover of the coloring book?
The company that published this, the Saalfield Publishing Company, started producing children’s storybooks and such back in 1900 and ceased operations in 1977, it’s library and archives were purchased by Kent State University. At least it stuck around long enough to give us some nice Star Trek memorabilia.
A big thanks to the Vintage Toy Archive Tumblr for the image you see above. Hop on over and check them out!