This book sends absolutely the wrong message, in more ways than one. Basically, the main character is upset, and the only thing his "friends" tell him is that he should smile for them, oblivious to the possibility that he might have a legitimate problem of some kind, or that feeling sad is even okay in this aquatic world. They don't want to deal with his feelings. Then a stranger arrives and kisses him on the face, which magically fixes the problem, suggesting to impressionable kids (as other reviewers here have pointed out) that going around kissing people you don't know is acceptable and in fact desirable. My video review goes into more detail.
This book sends the wrong message to impressionable children. Basically, when the Little Rabbit gets the titular red wings, his mother and all the other animals reject him as a stranger and he is forced to undo his wish in order to fit in again. It teaches kids that being different is bad. My video review goes into more detail.