I like that airbnb allows room for creativity, you can change and transform their logo's colour, stroke etc as long as you keep the same shape.
The shape is meant to represent a lot of things combined into one: people, places, love and the letter A, you can see this in the first image. This makes sense and works well.
Myself and Andrew have discussed this and we like the paint brush stroke, especially for an app because it's fun and inviting.
