I've not seen the sketch but I have read Aimee Lou's reaction to it.
As a person with a wide gap in my front teeth I was constantly mocked and bullied as a child and teenager back in the seventies and eighties. This has had an impact on my life, although, now in my fifties I know longer give a fuck about what people think of my looks.
However, for me, this just represents the attitude that is still alive and appears to be thriving that taking the piss out of someone's appearance is acceptable, it's not funny, it's bullying.