White people wiggle is a term that is used to describe white people's shitty dance moves that should never be seen and never exist. (BTW this is coming from a white person)
An example is:
Billy: 'What are those kids doing over there?'
NaNa: 'Those white dudes harlem shake'
Billy: 'Please make them stop!'
NaNa: 'Those white people wiggle haha'
Billy: 'Yo why you laughin?'
NaNa: 'Because those white dudes harlem shake'