Everyone has emotions and eyebrows are particularly useful in helping express these feelings -even when it comes to dogs. Of course, they aren't just useful for emoting, they're also great for a laugh and this compilation of dogs with fake eyebrows is also great for crack ups.
My old pooch had small eyebrows that were pretty expressive and I've seen a few with natural markings that look like eyebrows, but none of them look this over the top ridiculous.
Via Laughing Squid