What does the phrase peel onion mean?

"Peel an onion" is a verb used in Australian slang to describe crying from emotion or laughter.

Like cutting or peeling an onion can also cause a person's tear duct to react and produce tears, this phrase refers to when a person starts crying in a comical or dramatic way, similar to how tears might flow when peeling an onion. It might imply the individual cried uncontrollably, like removing or stripping away emotional layers like peeling an onion's layers. While it generally doesn't relate to onions, it highlights an emotional burst akin to peeling an onion's multiple layers, bringing on tears.