Huh. Weird. It's showing them as options if you click in (sometimes cheaper than the headline option) but if they're the only option under the price point it doesn't seem to show them (set it to Stansted to see).
EDIT: Ah, I found the problem (I suspect this is a bug in Google's flight thing). They had carry-on bags set to 1. If you set it to 0 it shows flights (mostly Ryanair) to almost everywhere in Europe. It may be getting tripped up by Ryanair's wonky treatment of carry-on bags (you can add 'priority boarding', which gets you a carry-on, as an extra fairly cheaply, but if you want it as a headline feature it comes bundled with a bunch of other stuff).
Even with this option off, though, it's still not showing easyJet.
EDIT: Ah, I found the problem (I suspect this is a bug in Google's flight thing). They had carry-on bags set to 1. If you set it to 0 it shows flights (mostly Ryanair) to almost everywhere in Europe. It may be getting tripped up by Ryanair's wonky treatment of carry-on bags (you can add 'priority boarding', which gets you a carry-on, as an extra fairly cheaply, but if you want it as a headline feature it comes bundled with a bunch of other stuff).
Even with this option off, though, it's still not showing easyJet.