[All] Sort photos of 'Jeonghan', a preservative human, by age

In the Seventeen episode of Business Trip 15 Nights, there was a problem with sorting Jeonghan's photos in order of age. Everyone, try to guess it!

Vernon, the party who had to solve the problem, chose the order 1-3-2-4.

So what is the correct answer?

This was the order~ Looking at it like this, number 1 seems a bit difficult? But I can't tell 2, 3, and 4 apart at all! I think the title of preservative human is fitting ㅋㅋㅋ