6-7 He has great genetics with shape and insertions/locations of muscles. The pics also look airbrushed. Looks pretty good to me.
He may also not always be in that shape. That may be a photo shoot diet down. Either way, looks awesome.
On a personal note. If I were that small waisted, I'd probably be happy with that size, but being HUGE in the hip area, I NEED to be heavier to look big(ger). It's all about the proportions. I have big swrists, big waist, just a large frame and I really need more muscle to fill out my clothes. A tiny waist and wrists etc... you can get away with that stuff and look awesome. I was'nt happy at 240's... at 250 I was starting to get content with my build. I've also never seen single digits these days. lol