"That's my wallpaper."
As anyone who grew up with a younger sibling can attest, imitation is the sincerest form of annoyance. Sure, your heart skipped a beat when you saw your friend's jewel box of an entryway smothered in the most perfect, unique, offbeat-but-not-too, beautiful-but-not-cloying, stylish-yet-not-design-blog-cliché, so-YOU-you-just-never-knew-it wallpaper. But the reason it's so unique and perfect is because your friend spent a year shopping around for it, and the reason she spent so long looking for something nobody had is because she wanted something...nobody had. So even though she would never say anything, at the risk of sounding petty, let her have the wallpaper/haircut/baby names.