Answer:
1. A girl flipping/holding a blanket
2. The problem in the picture is, it tricks people. It's an optical illusion.
3. Research, or having very good eyes.
4. Optical Illusion, it tricks you that it is the ocean, but it is a blanket which its design is inspired by the ocean.
Explanation:
An optical illusion (also called a visual illusion) is one which shows images that differ from normal reality. The information gathered by the eye is processed in the brain to give a perception. That is normal, but in these cases the appearance does not tally with a physical measurement of the stimulus source.
Optical illusions often occur due to mistaken judgments or errors in vision. For instance, a bright object often appears larger than a dark object of the same dimensions. Or, when objects of contrasting colors are placed in close vicinity, it plays tricks of movement and color definition on the eyes.
