This is a perfect example of a PSA being done right. The actual subject matter is covert, allowing it to be published, but the reader that this message is intended for will understand it perfectly. The more mature Bob seems very tuned in to what Frankie is feeling and may be speaking from experience. The PSA appears to be about sexual identity confusion, but it could be just about teen angst and feelings about socialization. It certainly seems to operate on a few levels. I have no idea how socially sensitive the editors were in 1958 or what the agenda was other than education. Like in my previous post, What Is Your B.Q.?, the PSA seemed at odds with the main borderline racist content of the book. The book this PSA appeared does also, which features traditional stereotypical male roles.
It would be nice to think that the editor was speaking out to kids on multiple levels and with a bit of subtlety considering the limitations of what could be said and shown in the Comics Code, but who knows? The PSA may be just what it appears to be or can mean what you want it to...either back in 1958 or today.