Baking tray on the shelf below?

[MikeWozniaksMohawk]

Can anyone explain why the instructions for some frozen pizzas say to put a baking tray on the shelf below, while the pizza goes directly onto the shelf? Is it to do with heat conduction? I generally ignore it because it seems pointless but happy to be told otherwise!

(yes I’m bored)

Catches all the melting cheese etc rather than it welding itself to the oven floor

Well I do it to catch the dribbly Cheese.

I always assumed it was in case any cheese/toppings dropped down. The tray would catch them for easier cleaning...

Helps to keep your oven clean by catching any melting cheese that falls off the edge of the pizza above!
Tbh, it's handy to always keep a tray or tin foil at the bottom of your oven for this reason.

Not for heat conduction but just to catch the drips IMO as well.

Oh! I just have a removable oven liner at the bottom of my oven for that purpose. I did wonder if it was just for drippy cheese. Just felt like a waste of a baking tray for only that!