1. Seeing the hidden picture. You can see the old man, but can you see the hidden picture?

The old man and the two lovers - father time | Optical illusions pictures,  Cool optical illusions, Optical illusion paintings
source: https://www.pinterest.co.uk/pin/239887117623635079/?amp_client_id=CLIENT_ID(_)&mweb_unauth_id=%7B%7Bdefault.session%7D%7D&simplified=true

2. Putting together a puzzle without knowing what the picture on the front of the box is:

Hands of an elderly lady solving a jigsaw puzzle
source: https://www.jigsawpuzzlequeen.com/are-jigsaw-puzzles-a-waste-of-time/