If one product says "5g fat / serving [serving size: 40g]" and another says "4g fat / serving [serving size: 30g]", many many people will think that the second one has lower fat content.
If these were normalized to 100g, it would be clear that the first has 5/40*100 = 12.5g of fat whereas the second has 4/30*100 = 13.3g of fat.
An excellent example of "serving" stupidity. How big a hand? Child's hand? Adult's hand? Bodybuilder's? Woman? Man? Full? Kind of full?
I have absolutely no idea what a "serving of cheese" constitutes.