Shadows are harsh, and this has the feel of more of a snapshot than a picture whose composition was carefully thought out -- I say this because of the harsh light and blown out highlights on the bike helmet combined with the shadows on the face. Cute puppy thought! :)
not a very compelling snapshot. focus is soft (esp on the dog where you can't see her eyes - but nice helmet!), the background is better lit than the subjects. as a portrait it's okay, as a portrait that evokes 'transportation' its even less effective (and i'm not a stickler for meeting the challenge subject).