Underfish, as has been pointed out
Easyjet is a point to point airline-so you are flying to the uk. not via the uk.
you do not TRANSIT the UK because each flight you take is a separate booking and a separate sector with different rules. This is different from a 'legacy carrier' airline even if you have to change airports for example between London Heathrow and London Gatwick with for example British Airways.
Point-to-point airlines such as easyJet and Ryanair have separate rules and are companies with a different business method and operation when compared with major airlines like BA, LH, SU etc. This has NOTHING to do with the entry visa requirement, because you are NOT TRANSITING the UK, simply flying to it, and then taking another flight away from it.