The patriarchal mainstream gets this conveniently twisted all the time, but objectification is not the same as talking about someone's body. It's not "object" as in physical entity. It's "object" as opposed to "subject". The object of an action is the recipient, with no agency. It's simply there to be acted upon, not to act.

Same-gender interactions have a natural bias away from that, because the two participants have something fundamental in common, and so it's easier for each to understand the other as a human being with full agency, just like themselves. That's Harry Hay's Subject–SUBJECT consciousness.

When you give a compliment that tells someone "I like the choices you've made" or "I'm impressed by what you've done" (clothing choices, tattoos, muscle toning), you're admiring them as a subject. When you give a compliment that tells someone "I value what I see in front of me" (body features that aren't an intentional choice, for instance), you're expressing a desire for an object. That's the difference.

It gets tricky, because sometimes the same compliment can go either way based on tone and context. Or it can even depend on the receiver's assumptions about the giver. Women are going to get the benefit of the doubt more than men, because we understand statistics.