Focal length and distance to the subject plays a big part in how a face is rendered. For those who want to learn more about this, this is a decent page, and it ties directly to the video: SAME GUY made both the written web-based page, and the video.
The Slanted Lens ? Episode 24 | KesslerU
And here's the video...and if you watch the video, you can see why a 70-200 is a more-versatile tool than ANY prime lens.
the video is entitled
How Lens Focal Length Shapes The Face and Controls Perspective
The idea that "Primes let you become more creative," is wildly off-base. No, primes do not "let you become" anything, except LOCKED IN to their one,single rendering characteristic and their one, single focal length. Primes lead to images that ALWAYS look "the same"...same,same,same,same. What a prime lens does is it never varies its angle of view, so it forces the shooter to shoot from the same exact distance every time. Prime lenses allow the shooter to pre-estimate angle of view, and to shoot the same way, over and over, from distances he has come to know through constant repetition and constant use of a one-trick pony. You could say that using a prime lens allows the user
to be very efficient, and to do the same thing over and over again, without much need for experimenting. That's not really being creative--that is working within the constraints of a lens that NEVER VARIES, that is always the same thing, year after year. I shot primes mostly for 20+ years. You need a LOT of them to be truly creative: I carried a 24,28,35,50,85,105,135,180mm, and a 200. And two bodies and a couple flashes. Total daily bag weight? 18.5 pounds on the scale with the 180 eliminated and just the light 200mm in the bag--and that was with 1980's SMALL, light compact Nikkor primes. Over 20 pounds with the 180mm/2.8 in the bag. Using prime lenses forces you to either work within their constraints, OR to take sub-optimally framed pictures in fast-moving situations.
Focal length flexibility and versatility is what a zoom brings; a prime brings the same angle of view every time, so you start to work in a rutted, routine sort of way, because--the lens FORCES you to stand X feet away to make Y kind of images. I do not see how that is creative; I see it as efficient, and possibly leading to work that is very much formulaic and or repetitive. I grew up shooting seriously in the 1980's before zooms were anywhere as good as they are now, and with basically a real upper ISO limit of 400, with shadow detail, and with primes that were very much sharper than the zooms of the day. I would not be surprised if the 70-200 VR-II is actually sharper than the 135/2 DC is at say f/3.2 to f/11.
Allow me an analogy: I have a wardrobe consisting of of five pairs of slacks, and five sport coats. I can mix and match.>>> 70-200mm zoom lens.
I have ONE single pair of gray pants and ONE, single gray sport coat. >>> Prime Lens.
Now, I will make the statement: Owning and wearing just the one pair of pants and the one jacket allows me to become more creative with my fashion sense.