The cabin crew stand at the front of the plane, and either play a recording or make an announcement saying you can buy a lottery scratchcard for €2 or whatever, with some of the money going to charity. They then walk down the plane "scratchards? scratchcards?"
They repeat this with a collection for charity (no scratchcard), a promoted drink, and some sort of food.
I think this is mostly unique to Ryanair (in Europe), I don't remember Wizz Air, Norwegian or EasyJet doing this. Part of Ryanair's marketing is to make the experience worse than it needs to be, so you know you're saving money.