Shadow stripes are created by measuring, laying out and taping off a wall.  First a base colour is applied in a matte or eggshell sheen.  Then the stripe is the same color but a glossier sheen.  The effect looks a bit different depending on what angle you are viewing it. Viewing straight on you see virtually no effect at all – viewing on an angle you see it clearly.  In the photo you will see maximum effect on the left, and less of the effect on the right.