Bows on underwear are a standard of the most lingerie ranges - it's something to do with that whole "if you undo that bow my underwear will totally fall off and I'll be all nekkid!" thing. Of course most bows are purely decorative and undoing them is more likely to result in loose threads than nekkidness.
The bow detailing on these knickers is particularly pretty:
Not the sort of knickers you'd wear under low cut jeans or figure hugging/sheer skirts obviously, but deliciously pretty and sexy nonetheless.
The Brittany ribbon trim brief is £3.00 from boohoo.com, and all their knickers are also 3 for the price of 2 (if you needed more reason to by some!).