I have the Mayday signal mirror. It is not the same mirror you are asking about but it performs well.
Mayday Signal Mirror

I have tested this mirror with an airplane and a 2x3" mirror from the NRA survival kit. I am in the Civil Air Patrol and set out a practice Emergency Locator Transmitter (ELT) during a practice search exercise.

When the plane got close enough I began signaling; alternating between the two mirrors. The crew in the plane was able to spot both mirrors and reported that the larger mirror was easier to see. They didn't say that the larger mirror was vastly better, just that it was easier to spot. I feel that the performance of both mirrors was acceptable.

I did notice that aiming was quicker and easier with the larger mirror. I honestly can't say if it was me, or the mirror.

I now use the small mirror in my hiking/backpacking gear and have gone to the larger mirror for my flight bag.

Randy