Her friend has decided not to enjoy the cardboard with her. Her friend's shoes are already well-cushioned and comfortable enough, and also her friend is afraid she'll never be able to get up again while wearing those things.
Though apparently it can also provide an ingredient for a mixed drink:
3 oz. (Soy vodka) Vodka
4 drops Grenadine
1 oz. Milk, Soy
In a cordial glass add 3 oz. of vodka and 1 oz. of Soy milk. Stir until it is nicely blended together, if you desire a more milky appearance add 1 more oz. of soymilk. Lastly add 4-5 drops of grenadine for a "bloody" effect.
What's actually in that girl's Rice Dream is anyone's guess.