You Do Need power plug adapter while traveling from Réunion to Laos.

Here is Why You Need An Adapter

The outlet and plug type used in Laos are A, B, C, E and F and in Réunion are C and E. This is how they look like.

Réunion

In Réunion, outlets of type C and E are in use.

Type C

Type E

Laos

In Laos, outlets of type A, B, C, E and F are in use.

Type A

Type B

Type C

Type E

Type F