This is what as a Norwegian we would just call "American" pizza. For a "traditional Norwegian" pizza it would be a homemade square one cooked in the regular oven with thick bottom, tomato sauce, minced meat, and generous cheese on top. It was intended to feed a family with very simple tastes and to be fairly cheap to make.

While American style pizza is popular, Italian style is also very popular in urban areas.

PS the white sauce is what we call "rømmedressing", which is a sourcream based sauce with garlic and some other spices. It's eaten on both types except not really served at fancier Italian restaurants.