POWDER ROOMS BY DEFINITION are short on space, but that doesn’t mean they have to be bland little boxes. Lately, they’re bursting with personality. For these contained, single-use rooms, designers say pretty much anything goes, and homeowners are buying in, taking risks they wouldn’t normally agree to for other parts of the house. The powder room has even been likened to a folly, a decorative structure once built on the grounds of English country estates as a conversation piece. Here are four modern-day examples of tiny half baths that, like those whimsical follies of yore, really make a statement.