Can you compare these two photos?

On her Facebook's profile, Ms. Chanbo Keo has recently

posted two photos for you to compare.

This photo was taken in Cambodia

This photo was taken in North Vietnam

Hint:
What are the same and are different?

Have you taken any notice of the photos?

Can you guest when were they taken?

What are the same and what are different on the flags?

Can you give answers to her questions?