We need to have an emergency TIN DEBATE now!

I have always, in my whole life, dumped my ingredients into the LARGER tin, then seal the larger tin with the SMALLER tin on top. Smack , seal, and shake. It has brought to my attention that some fellows smack the LARGER tin on top of the SMALLER tin.

What is going on?!?!?!?

So I must ask, SMALL ON TOP OR LARGE ON TOP?