Okay, here it is!
Blue water: Intelligence and emotional (The former because blue symbolizes calmness, trust and intelligence, and the latter because water at times can be crazy unpredictable, kind of like emotions)
The key: Curiousity
The mermaid: Fun (I like to think the mermaid's symbolic of letting our hearts and our passion overrule the analytical mind, and that sometimes what one may think is fun doesn’t have to make sense.)
Windmills: Chill (the windmill is a universal symbol of life, hope, serenity and resilience.)
The lanterns: Just put those there for no reason.