Yeah, I think he's flexing there. It's just hard to tell because he doesn't have any visible muscle definition.
Totally agree with everything said. I like the fattish look in guys myself.. think Volker in season 2 SG:U.
It's weird to always notice how Nimoy seems scrawny in TOS when he's a perfectly normal looking man.
Well, I like the look of people with a fairly normal body fat percentage, which is why I mention not finding underwear models with 0% body fat attractive (or many people on tv or in movies these days).
I think Nimoy looks scrawny next to Shatner because of Shatner's very different body type with the broader shoulders and because Nimoy's a few inches taller.