1. Playfully quaint or fanciful behavior or humor.
2. A whim.
Shabby chic decor is a fun theme to follow because there is room for so many personal touches. It should be fun for you to decorate in this style and it should be fun and interesting for guests to enjoy your finished project.
When I hear the word whimsy I immediately think of fairies for some reason and I’ve seen paintings of them and fairy figurines used as accessories in a shabby chic theme. Sometimes decorating in this style can take on an extremely feminine character and if you like frills, lace garnished fabrics and lots of pink and pastels, fairies might be just the thing you’re looking for, otherwise I would encourage you to use the dictionary definition of whimsy and look for accessories that you like and say something about your hobbies and interests.
Explore you own surroundings first. Pull out boxes of memorabilia, trinkets and keepsakes and see what you have on hand. Adding a vintage style frame or otherwise sprucing up your own treasures are a great way to truly personalize your decor and make good use of the goodies hiding out in the dark recesses of the attic. Be whimsical.