Depends on the style, the consistency of the sauce, and the dough, how much you can get use without making a mess. That looks way on the high side to me, though their sauce might be very dry (thick) which might let them get away with it.
Normally on my thin-crust pizzas with a somewhat watery sauce (what you get when you use fresh tomatoes, or canned crushed tomatoes, or anything along those lines without mixing it with lots of paste) you can see about 50% of the dough through the sauce, it's that thin, but if I make it much thicker the toppings get very... slippy-slidey.
Normally on my thin-crust pizzas with a somewhat watery sauce (what you get when you use fresh tomatoes, or canned crushed tomatoes, or anything along those lines without mixing it with lots of paste) you can see about 50% of the dough through the sauce, it's that thin, but if I make it much thicker the toppings get very... slippy-slidey.