You probably saw this Monday as A-listers made their way into the Metropolitan Museum of Art for the high-fashion event -- FO touched down with what appeared to be an infant cradled in his arms. As it turns out, though, it wasn't a kid ... it wasn't even alive either.

Frank had some sort of a robot with him -- which moved and blinked (and maybe even cooed?) like it was the real deal, but very much so wasn't ... on account of its slime green skin tone, among other tell-tale AI signs. It was weird -- but very on-brand for Mr. Ocean.

Dude's pretty enigmatic as an artist -- so him walking out with this machine in hand isn't all that nuts if you think about it. It was actually more of a shock just to see him there at all.

He hardly ever goes out ... but when he does, it's always a scene. As for what he himself was wearing, Frank had on a black Prada suit, accompanied by a custom cap, jewelry he reportedly had designed by his own line, Homer ... and, of course, his highlighter hairdo.