Cross sectional views are an essential part of architecture plans, indicating the relationship between levels of a building and giving an acurate picture of what can be achieved with the space.
They're also a favorite of illustrators, giving the viewer an intimate look at both the house, and the home. Admire the interior design and maybe catch a glimpse of the bustling activities within- it's just a little harmless voyeurism.
For more cross sectional fun, take a look at Scott Teplin's alphaville. Like all good cross sectional illustrations, there's plenty of visual stimulation.