Look at the weird pattern that appear on photo above, yes! it's called moire pattern.

In real life, moire almost never seen because quality of our eyes is the best. but for camera and lens that full of deficiency, moire appears oftentimes. It shows in hair, clothes, escalator and almost in all objects that have recur detail pattern which is tight and complex. 

In digital camera, moire happen because the way of light reach out the censor and how the censor interpreting that light. There are some effective tips to remove this moire that appear in your picture. The next article, i will explain about shooting tips to remove the moire. but if you are already have the photo with moire, you can use Lightroom to remove the moire, even you can't decrease it all.