You just need to read some of the comments underneath the video to realise there are rather a lot of people with the same ugly views as this woman.
They can't all have mental health issues
Some people without MH/drug issues can find their inhibitions are easily lowered when in a postition of relative anonimity. They can be far more extreme, aggressive, offensive or dismissive of other people's feelings/humanity when sheilded by a screen for example. But an awful lot of them will be far less forthcoming with their vitriol when they are no longer "invisible/untouchable". Unless they are in a gang which offers safety in numbers.Or sure that their audience will concurr.
Some people with MH/drug issues can find their inhibitions are just as easily lowered even when deprived of anonimity. Regardless of the fact that a lack of "invisibility/untouchability" and gang could lead to real life retribution given that the audience is highly unlikely to appreciate their views.
It is that profound lack of inhibition when expressing highly provocative opinions when deprived of anonimity and a posse (in conjunction with visual and verbal clues) that leads me to make room for possible MH issues and/or drug abuse in the case of the woman in the vid. Not her status as a racist.