By tapping on the clothing button, you can quickly customize your look by choosing a specific hairstyle, eye color, shirt, pants, shoes, and more — you can even make yourself appear to be crying or add a facial tattoo.
A lot of the styles and customization options are grayed out initially, but if you tap on the item you want and wait for 10 to 20 seconds, the new piece of clothing or pair of shoes will download and you'll be able to select it.