What happens if you decline the millimetre scanner in a UK airport?

Gov't guidance states that ‘...the individual must either be screened by an alternative method which includes at least an enhanced hand search in private...’ [0]. Is that just a standard pat-down, or is it more ‘eeny meeny miney mo, I wonder where my glove will go?’

[0] https://www.gov.uk/government/uploads/system/uploads/attachm...