In a spacious, well-lit art gallery, three friends, Dakarai, Hyeon, and Ivanna, are looking at paintings displayed on the large, white walls. Each painting is placed with considerable space around it, allowing viewers to appreciate the artwork from all angles. Dakarai, with a keen interest in abstract art, is currently standing still, engrossed in studying a vividly colorful abstract painting. Facing the painting means he is looking directly at the northern wall of the gallery.

To his left, which is the western direction, Hyeon quietly observes a collection of classic Renaissance portraits. She is positioned in such a way that she can see, from the corner of her eye, the eastern side of the gallery and partially the northern wall where Dakarai is, but her view is mostly focused on the portraits in front of her.

Meanwhile, Ivanna walks around a large, circular sculpture placed at the center of the room. She walks clockwise around this sculpture, which allows her a rotating view of the entire room. Assuming Ivanna completes her circle and returns to her starting point without stopping her walk, she will have had the chance to observe every wall in the gallery, albeit at varying angles and with different levels of attention.

All three friends are aware that there are four guards stationed in each corner of the room, but none of the friends have a direct line of sight to any of the guards due to their focus on the artworks. The guards are instructed to remain stationary unless they spot someone touching an artwork, at which point they are to walk to the center of the room.

Given this setup, explain what different sections of the gallery each person (Dakarai, Hyeon, and Ivanna) is able to see without moving from their positions. Additionally, indicate what changes if any of the guards were to walk to the center of the room. Specifically, detail who among the three friends would be able to see the moving guard and how their perspective on the artworks or the room might change.
Dakarai, who is facing the northern wall in contemplation of the abstract painting, has his back to the southern wall. From his current stationary position, he cannot see the southern or eastern walls directly. Due to his orientation, he can see parts of the western wall, but only peripherally as his attention is fixed on the art in front of him. His gaze is unlikely to include the corners of the room because his focus is narrowed to the painting. Thus, he cannot observe any guard directly.

Hyeon is adjacent to the western wall, with partial peripheral vision of the northern wall where Dakarai is, as well as limited sight of the eastern wall. However, her view is largely obstructed by the artwork she is studying. The southern wall is squarely behind her, making it invisible to her without turning around. Her vision is less restricted than Dakarai's since she can view two walls at once, albeit not fully. She will not notice any guards unless they move within her peripheral sightline, which would only be possible if the guard from the northwestern or northeastern corner moved towards the center.

Ivanna, as she circles the central sculpture clockwise, has a dynamic field of vision. At each point of her circumnavigation, she faces a different wall. Beginning her rotation facing the northern wall, she eventually views the eastern, southern, and western walls. Ivanna briefly sees each section of the gallery, including all corners where the guards are stationed. However, her view of any specific area is transient and dependent on her position in her circular path at any given time. She would only notice the movement of a guard if her line of sight aligns with a corner as a guard begins walking towards the center when she faces that particular direction.

Should a guard from one of the corners walk to the center of the room, the changes in what each person can see are as follows:

- Dakarai will remain largely unaware of the guard's movement unless the guard crosses into his narrow peripheral vision on the left side. This would only occur if the guard from the northwest corner walked to the center.
  
- Hyeon could potentially observe a guard moving to the center if the guard came from the northwestern or northeastern corner, as this motion would fall within her wider peripheral field of view. However, if her attention remains on the portraits, she might not notice the movement at all.

- Ivanna is most likely to spot a guard's movement, but only if she is facing the specific corner that the guard started walking from at the exact time of movement. Since her observation is in motion and staggered, her likelihood of spotting the guard depends on her position in the rotation relative to the guard's timing.

Each friend's ability to see different parts of the gallery or observe the movement of the guards is limited by their orientation and focus within the space. Dakarai primarily sees the northern wall, Hyeon sees the western and partially the northern and eastern walls, and Ivanna's view rotates with her movement around the sculpture. The possibility of noticing the guards' movement requires either a change in their own position or focus, or a coincidental alignment of their field of vision with the guards' movement towards the center.