Low willpower and willpower modifiers, most easily achieved with items like vitality potions or sweet memories drug. Alicia "affects" Aura's thoughts and effectively forces her in to the option, as you cannot decline them if the pink option is available. She also tends to exhibit more curiosity and enjoyment of the scene.
There are benefits, yes, as Aura receives generally double what she'd get otherwise in terms of sexual and lewdness increases. For example instead of 1 corruption, she receives two, she'll receive 2 lewdness, or lewd knowledge, or 2 breast sensitivity for example. Effectively the higher these numbers are the easier it'll be to make her perform future actions, especially pink instances.
Lewd Knowledge pink scenes are especially useful as they'll double the magic attack you're gaining from lewd knowledge. Between just two books from Roya's bookstore, you'll get 3 attack, and 4 lewd knowledge for 4 magic attack instead of 2 magic attack.
Some scenes have checks for certain fetishes as well, which are more easily reached by doubling your gains. For example in the refugee camp, the prostitute requires 5 exhibitionism to teach you her stance, which you can have 6 through just 3 interactions on day 3.
If you'd like an early game 'path' to achieve about 5 pink scenes on day 3, just ask. It's good to do imo.