what is the significance of this quote? "I'd like to just get one of those pink clouds and put you in it and push you around?"

This quote can be taken in two different ways. First, we see Daisy as she is; flirtatious, silly, and rather inconsiderate (she's leading Gatsby on). Second, the real Daisy is who we're supposed to see. She's unhappy, but non-committal; she's definitely falling under Gatsby's spell, but she's not going to look overtly serious.