If you are still searching, study the entire picture instead of focusing on one area. Look for unusual curves, outlines, shadows, and shapes that seem slightly out of place. Sometimes the hidden animal is formed by the space around an object rather than the object itself. Changing your distance from the screen or briefly squinting can also help reduce distracting details and make larger shapes easier to recognize.
The most satisfying moment comes when everything suddenly clicks. One small shape may begin to look like an ear, another becomes the head, and several curves connect to form the donkey. Nothing in the picture has actually changed—only your interpretation has. Once your brain recognizes the hidden pattern, it can become difficult to understand how you missed it before.