Definitely an attempt at butterfly. No style points here. Putin swims fly as most people do–influenced by the notion that it’s about raw power, rather than supple grace. Come to think of it, I wouldn’t bet against his choosing to be photographed swimming a “manly” butterfly as a demonstration of virility.
Like most people who have little understanding of the stroke, he’s diverting most of his energy into moving up and down, rather than forward, by lifting his head far higher than necessary to breathe.
His arms are tense and likewise clear the water far more than necessary.
We should always be mindful that any body part lifted above the surface weighs 10x more as a result of losing the ‘buoyancy benefit,’ than when it’s in the water. As you lift it higher, that energy cost soars as well.
He’d travel farther forward–and expend far less energy–on each stroke if he kept his head moving forward, while grazing the surface with his chin, as he breathes. And his arms would do a more effective job of transferring momentum forward if he recovered with a relaxed, wide, sweeping action–leading with the back of his hand rather than his thumbs, barely above the surface.