The itty bitty would make sure your bottom lashes don't miss out on the fun - this could be used for your top lashes as well. Also perfect for those stubborn lashes near your inner eye!
You'll notice there is one side that has the full brush effect and the other has regular bristles to "comb" out any clumps making the entire look more defined.
The biggest difference between this and the Big & Bushy applicator are the bristles. These have little ones mixed in with the longer ones making sure each lash is coated evenly and fully! Not to mention the length it will give your lashes.