I try to look at the searches done on my site every week or so. Someone did a search on "someone wearing a khanga". I didn't have any pictures, so I took out one of my khangas and had my daughter model it.
Here's the first picture:
Most East African women are seen wearing khangas over their skirts in this manner. The khanga keeps the dust and dirt of their nicer clothes.
Here's the same khanga being worn in a different manner:
My daughter has a t-shirt on underneath, but generally your wouldn't have that on. I've never seen a woman wear a khanga like this - this may be done in the privacy of her own home, perhaps. I did see this in a guide on khangas in a Nairobi bookstore. I wish I had bought the book...
One last picture of the African proverb on the back of the khanga:

To learn more about khangas, you can read my article
What is a Khanga?