In a spacious art gallery with a high ceiling and bright lights, three individuals - Kofi, Marisol, and Yi - are examining a unique, large abstract sculpture. This sculpture is positioned at the center of the main hall and can be appreciated from 360 degrees around it. Kofi stands to the north of the sculpture, gazing intently at the intricate design, utterly absorbed by the play of light and shadow upon its surface. Marisol is positioned to the east of the sculpture, taking photos with her camera to capture its grandeur from her perspective.

At the same time, Yi is walking around the sculpture in a counter-clockwise direction, pondering the artist's choice of materials. Yi started her walk from the south of the sculpture and is making a full circle around it to gain a comprehensive view. As Yi moves, she is also observing her friends' reactions to the artwork. The gallery is otherwise empty, save for a gallery assistant who is organizing informational pamphlets on a desk situated in the southwestern corner of the hall.

Considering the positions of Kofi, Marisol, and Yi, as well as their sightlines and movement, explain the following: as Yi moves around the sculpture from her starting position heading north, what is the sequence in which she will see Kofi and Marisol? Then, when she continues her path beyond Kofi's position and back towards her starting point, will there be a point where Kofi and Marisol are both out of her sight, and she is out of theirs? Also, how does Yi's movement influence her understanding of Kofi and Marisol's perception of the sculpture, given that she can see their changing expressions as she walks?
As Yi begins her counter-clockwise walk around the sculpture starting from the south, the first person she will come into the line of sight with is Kofi, who is standing to the north of the sculpture. Since she is moving in a counter-clockwise direction, the eastern side of the sculpture, where Marisol is taking photos, will be the last perspective she gains as she completes her circle.

After Yi sees Kofi, her path will take her to the western side of the sculpture. At this point, Kofi will remain in Yi's field of view because she is walking around the northern edge where he stands. Marisol, on the other hand, will temporarily be out of sight for Yi because the sculpture itself will be blocking Yi's view of Marisol while Yi is on the western side.

Upon reaching the northwest position, Yi will begin to see Marisol as well, as her line of sight extends around the edge of the sculpture. Yi's view of Kofi will become obstructed as she continues to move along the northern to the north-eastern side. To be specific, there will be a brief overlap when Yi will see both Kofi and Marisol simultaneously--this occurs as Yi moves from the northwest to the northeast of the sculpture, where the lines of sight to both Kofi and Marisol intersect her path.

Continuing her journey towards her initial starting point, Yi will have Marisol in view for the longest duration as she traverses the eastern side, while Kofi will be hidden by the sculpture once Yi passes the northeastern corner.

Regarding the second part of the scenario, once Yi moves past the northeastern point and continues southward, Kofi and Marisol will eventually be out of Yi's line of sight, and both Kofi and Marisol will not be able to see Yi. This will occur when the sculpture is directly between Yi and the other two observers. Yi's position, south of the sculpture and the others' positions to the north and east, will hide each person from the others' view. Specifically, as Yi moves from the eastern side of the sculpture to the southeastern part, Kofi will be obscured first followed by Marisol as Yi approaches the southernmost point.

Yi's movement around the sculpture also allows her to observe Kofi and Marisol's reactions from different angles at various times. This observation helps Yi understand her friends' perceptions of the artwork. For instance, as she moves to the northern side and sees Kofi's entranced expression, she gains insight into his appreciation of the intricate details. When she circles to the eastern side and sees Marisol taking photos from different angles, Yi can infer that Marisol is focusing on capturing the sculpture's grandeur. Yi's unique, moving perspective allows her to compile a more comprehensive and dynamic understanding of how Kofi and Marisol are individually experiencing the artwork. As Yi completes her circular path, returning to her starting position, the changing expressions and behaviors of her friends enable her to gauge their evolving interactions with the sculpture over time.