In the quaint village of Ilyria, there lives a girl named Eirwen who possesses a magical mirror that always shows the view directly behind the person looking into it, regardless of physical obstacles. One sunny afternoon, Eirwen joins her friends, Jai and Kasim, to play hide and seek in a field surrounded by high walls. Eirwen, while seeking, plans to use her mirror to find her friends hiding behind the walls.

As she approaches the center of the field where the game starts, she notices that Jai and Kasim have chosen their hiding spots: Jai is behind the northern wall, and Kasim is behind the southern wall. Eirwen must stand in the center of the field, close her eyes and count to hundred before she can start seeking--those are the rules of their game.

Once Eirwen starts seeking with her eyes open, she uses her magical mirror. As she holds the mirror before her face, what does she see, bearing in mind the properties of the mirror and spatial relations in the village field?
Eirwen is standing in the center of the field, facing north towards the wall where Jai is hiding. On her first attempt with the mirror, she would see the view directly behind her, which means the southern part of the field. However, since the mirror reveals what is behind the person looking into it regardless of obstacles, she would not see Kasim, who is behind the southern wall, but rather the unobstructed view of what lies directly opposite of her current position on the other side of the wall.

Now, if Eirwen turns around slowly, the mirror's view will change according to her rotation. As she turns to her right (eastward), initially the mirror would show the western edge of the field, then the northern wall, and finally the eastern edge as she completes her quarter turn. During this time, she would not see Jai, since he is hiding directly behind the northern wall and Eirwen's perspective shift caused by her turning hasn't yet presented a direct line of sight to Jai's position.

Continuing to turn towards the south, Eirwen's mirror would show the field's northern part, then the central area where she began, and eventually the southern wall. It is at this point, if Kasim has not moved from his hiding spot directly behind the southern wall and within the range of the mirror when directly facing it, that Eirwen would see Kasim in the reflection because the mirror now reflects the view directly behind her, which includes the area where Kasim is hiding.

Finally, as Eirwen completes her rotation to face west, the magical mirror would present her with views of the eastern wall, then the southern wall, and lastly the western edge once more. 

Thus, if Kasim remains stationary and in the direct position behind the southern wall from Eirwen's starting point, he will be visible in the mirror when Eirwen faces south, as the mirror will show what is behind her, ignoring the wall that is meant to conceal Kasim. After realizing Kasim's location, Eirwen can continue to seek out Jai using the same method of turning and viewing through the mirror until she captures a glimpse of him when there are no obstacles in the direct line behind her.

Jai, being behind the northern wall, will only be visible when Eirwen faces directly north, at which point the magical property of the mirror will reveal Jai's hiding place, again disregarding the wall that provides his cover. If Jai remains in his spot during Eirwen's full rotation, she will see him upon facing north after completing her full turn. This rotation and the uses of her magical mirror allow Eirwen to locate both of her friends without moving from her spot in the center of the field.