American Beauty, through its use of symbols and the title of the film itself makes us examine the characters and their philosophies (American dream, their concepts of success, beauty, etc.) both as they are and as they are perceived. No one in the movie is actually as they seem. In the end the creepiest (Ricky) is the nicest, the successful wife is an unstable wreck, and the American beauty is rather plain.
The red rose pedals, which appear several times throughout American Beauty are a symbol for love, sensuality, and vitality. However it is important to note that throughout most of the movie the red roses are implicitly an illusion. The red roses in the context of an illusion come to stand for a sugar coated reality.
By sugar coating I mean that which covers up the natural stimulation (taste, sight, touch) by "sweetening" it. In all but one of the scenes, the red peddles are around Angela covering her naked body in a way which makes what ever lays beneath, that much more enticing, through the use of sensual reds and the sexiness of mystery. Not to mention extreme spectacles which often accompany Lester's dream scenes.
However in the scene where Lester finally gets what he has been wishing for Angela has no red peddles around her. Unlike her breasts in the first scene which were covered up with vibrant pedals, this scene exposes her body for what it is, we like Lester start to feel like Angela may not have been all she was cracked up to be. It is not that Angela isn't beautiful, it is that no one could live up to the god like expectations that Lester's wild fantasies created.
After Lester finds out that Angela is a virgin and not at all what he thought she was he goes out to the kitchen and picks up a picture of his family. As Lester looks at a photo of his family saying "man oh man …" a bucay of red roses (exact to those shown earlier) are shown for about 5 seconds. These roses unlike all shown previously are real, not a dream. Also unlike the roses shown earlier they are associated with his family and not Angela. In this context the roses do not represent sugar coating but real love, sensuality, and vitality. Seconds latter we see a puddle of red blood. Shortly after we experience, by video montage which is Lester's life flashing before his eyes, the love, sensuality, and vitality which the picture represented.
The theme of things not being what they seem is not isolated to Lester's view of Angela. Several times throughout the movie Carolyn says You have to project success at all times to eventually become successful. Lester also comments to Ricky's Dad that his marriage "… is just for show".
Many of the characters seem to obsess over how people perceive them but show little care for the reality of things. Ricky's Dad who hates homosexuality, and lets it be known several times throughout the movie, in the end turns out to be interested in men sexually. Carolyn and Buddy are obsessed with seeming "successful" and having others think they are part of a "normal" family, it is the struggle to seem this way for both of them which makes them emotionally unstable, and tears them apart from their families.
American Beauty through its contrast of reality and perceived reality makes us examine what American beauty is, the American Dream, and how real the promises these narratives offer really are.