You Do Need power plug adapter while traveling from Niue 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 Niue is I. This is how they look like.

Niue

In Niue, outlets of type I are in use.

Type I

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