I might be wrong, but I think Nylander is bit off a show off and likes to look that way. Which is okay and good for us, but like said it's still unnecessary weight for a hockey player. Would I like to see Marner to be build up that way, yeah sure, but rather all legs and you can't judge that from that picture. Also if Marner is ectomorph like it seems, it damn hard to gain muscle and he probably loses it bit faster during the season. I think Selanne, who was fitness freak, said that he always lost few kilograms of muscle during season. You can't train hard enough and playing +80 games takes it tolls to your body. You can try to slow it down and it easier to gain it back during summer, after you have once put it on, but it's still slowing that bulking process down.