Ableist folks like those on this thread are why I have to specify 'autistic meltdown' instead of just saying meltdown.
Even then, folks who aren't neurodivergent still don't understand.
I am 39. I experience both autistic meltdown and autistic shutdown.
Neither are funny. Both involve a distressing lack of control. Frightening, distressing, embarrassing, shaming, soul destroying - these are all things other neurodivergent folk like myself feel about actual meltdowns.
A toddler tantrum might seem the perfect behaviour to describe with the term meltdown, but it very much is not the same. Similarities in places like reasons for, and processes, but they still are not the same.
The jumper would be something my two autistic children and my autistic self could laugh about between us, but I very much would not wish to encourage NT friends or strangers to join in on that because it's not appropriate.