It's a birth defect - Big Ed Brown from 90 Day Fiancé has Klippel-Feil syndrome, which makes his body look different from others.
I don't watch it, but making fun of someone for his looks, which he can't control, is a doozy, so I hope they laugh because of his antics and not his body. Would be kinda cheap otherwise.
"90 Day Fiancé star Ed "Big Ed" Brown is working on himself mentally and physically.
The interior designer, 55, opened up about his insecurities stemming from having Klippel Feil syndrome, how he's been combating them and his fitness journey that resulted in a 21-pound weight loss."
https://people.com/health/90-day-fiance-big-ed-inspiration-people-with-klippel-feil-syndrome-21-pound-weight-loss/
"I grew up with the condition called KFS - Klippel-Feil syndrome- where it looks like I actually don’t have a neck," Big Ed explained. "But I do. I have 3 vertebrates that are the size of 2 when most normal humans from this world have 7. And I have a bigger than normal chest cavity so I’ve been bullied all my life.” While some viewers have been cruel about Big Ed's appearance, he is used to receiving criticism and standing out."
https://screenrant.com/90-day-fiance-big-ed-neck-rare-disorder/