The overall diameter is the same so the actual wheel and tyre combination is no different. However when you have a wheel this size it does a sort of optical illusion and the wheel looks bigger.
I’m not too bothered about the change. I think we’ll get used to it after a few races. I’d prefer maybe a slightly bigger sidewall but that’s it, the front tyre/wheel looks slightly awkward in my view.
I tried to think of this in reverse. How would Le Mans prototypes looks with current F1 tyres? they’d look silly too. So it’s a case of what you get used to.
I believe the reasoning behind it is purely marketing. Like hybrid engines. Pirelli want more of a road car link and low profile is more in tune with sports cars, etc than the high sidewalls they have now. Oddly though it actually does less for marketing because the smaller sidewall means smaller logos, which means they are probably harder to see.
What I find interesting about all of this is the technical change, this will make a huge difference in suspension design, setup and how the car behaves over bumps. Whoever gets this right will have a huge advantage. All the teams are probably running tones of simulation data with these wheel/tyre combos to find out what they’d be like.