What's the difference

What's the difference? There are four pictures for each question , One of them different , come to find out it !

============ Game features ==============

1. Simple, fast-paced

2. The most appropriate to pass the time

3. Brainstorm, brain activation

4. Cute style , the public image

5. The young and old , healthy game

6. Category rich , ever-changing

7. The quiz is updated regularly