It’s boring at first and nothing seems to be happening. That is, what is happening is events that are much more interesting to participate in than to watch. Well, Poppy's wardrobe is still interesting to watch, with this approach to experiments, "you can not bother, if you get horror, next time there will still be something else."
And then it turns out that the film itself is an occasion to reflect society's expectations of women. Adult aunt, whose clock is ticking, suddenly dares to live as she likes, not getting involved in children, mortgages, retirement plans, and not even caring about the fact that her sociability and cheerfulness someone can lose their head. “We are responsible for those we have tamed.”
In general, the film is for good girls who need to know that the world will not collapse if they follow their desires more often, rather than constantly looking at the opinions of others.