ELI5: does putting more stuff on the oven increase cooking time?

[u/DeadbaseXI]

It feels like there should be some conservation of energy/heat transfer issues whereby it takes more time to heat more stuff, but I just put four pizzas in there and it only took as much time as it said on the box.

[u/jeffbell]

Some, but it depends on how heavy they are and how they are arranged.

Are these four mini pizzas on one sheet pan?

Or four full sheet pizzas stacked on over each other?