What does it mean to give roses to another player?

The Rose Event is a competition where the person who receives the most roses in their battlefield gets the top prize (you can see this by clicking the cupid statue in your base). When you give roses to another player, you earn chocolates at a 1:1 ratio (e.g. If you give 10 roses to another player, you get 10 chocolates). You can then exchange the chocolates for prizes in the valentine store (again by accessing the cupid statue on the bottom-left of your base)