Sometimes do you feel like something or someone looks familiar?
The reason is we did have seen these things before or just the intros of them. However, our brain only focus on things needed to be focus, we may selectively forget some matters, while when we see them again, the impression gets deepened, making people think that they have seen them before.
In reality, many people make use of this idea, such as using body language to make descriptions, even though the information may not be precise, the impression can be made subconsciously, so when introducing formally, people would feel much more acquainted.
this APP applys the same theory.
Using instruction:
1. Divert the persons attention, let him focus on somewhere else (prefer somewhere pleasant )
2. Within his sight range (stay away from where hes focusing), press the screen to show subconscious pictures.
3. Repeat the action to deepen subsonscious impression.
If the person discovers, put fingers off the screen immediately, show irrelevant picture to disguise.