The keys and locks are in reference to when Alice falls down the rabbit hole, lands in a tiled hallway, sees a little door and then needs the key to open it. She finds a bottle labelled 'drink me' and shrinks, then eats a lolly labelled 'eat me' and grows huge, then cries and cries until she makes an ocean of tears! I was quite horrified by Alice's adventures when I was young, but now that I've seen the movie as an adult, I realise Alice WAS quite precocious, and she HAD wished for an adventure, and she really was quite capable of coping in her Wonderland. I always thought she was meant to be 7 or 8, but now I think she was intended to be 11 or 12. The blue on the cards is a link to Alice's dress, and the black stripes link to her headband. I hope you can see the links as I do!