She is holding a daisy, which represents innocence, and she is colored in monotone gray and surrounded by a myriad of vibrant, beautiful flowers. From her downcast expression, you can tell she feels inferior compared to all the other flowers, which shows how the pressures of others impact an individual.
The outside of the house is vibrant and lively, a stark contrast to the darker tones and depiction inside the house. This shows that what one sees on the outside of a home may not be the whole story.
This shows that an individual can be isolated in society even when surrounded by people: the girl is fenced in with the hard showing society's polluting thoughts toward teenagers and how damaging they can be to a teenager's character.