spot the difference
noun1
A type of puzzle in which the object is to find a certain number of minor differences between two pictures, usually printed side by side, that are otherwise identical.
- The cartoon dog made its debut in half-term week in October, featuring on promotional children's tickets as well as fun children's activities such as colouring sheets and spot the difference.2022 November 30, “Stop & Examine”, in RAIL, number 971, page 87: