I hadn't realised that it was not a story book, but rather a sketch book with only one or two comments or captions per page.
Well, apparently I was on the right track mentioning that only the very wealthy could afford to loll about in the summer in special sporting or vacation type locations, during those old days. Bar Harbor, Maine, shown in all its glory, was where the super rich spent summers sailing and vacationing during the late 19th and early 20th Centuries.
The sketchbook seems to have a cynical message, that dallying about in summer, with the opposite sex can be fun, but can lead to marriage, which will shackle young, virile and happy men to one woman for the rest of their lives which will likely not be nearly as rosy as it was beforehand. So, beware young men! And the young woman in the picture shackled to the young man looks unhappy, too. So, I guess this is a "philosophical view" as a message of warning to vacationers of both sexes seeking romance.