Seem adj vs seem to be adj

John seems happy.

John seems to be happy.

Do you guys have any idea what the difference is between the two?

One would say there’s little difference in meaning, but I think that, since the forms are different, there should be at least some difference.

To me, it feels like the 1st one has to do with a direct perception than the 2nd one. I mean, the 1st one sounds to me like the speaker is looking at John or directly perceiving him in some way, while the 2nd one doesn’t have to satisfy this condition. I might utter it in John’s absence, though not the 2nd one.

What do you think?