In a spacious room, there are four individuals: Keiji, Nia, Olamide, and Priya. In the center of the room, there is a large, opaque cube that is taller than everyone in the room. Keiji stands directly to the north of the cube, facing south. On the other sides of the cube, Nia, Olamide, and Priya are standing, each facing the center of the cube from the south, east, and west sides, respectively. Without moving from their spots, each person starts to describe what they see. Keiji begins to describe the appearance of the person directly across from him, but realizes something is obstructing his view. Nia mentions seeing Keiji's colorful shirt, which has a distinct pattern recognizable to all. Olamide describes the cube's west face and the items placed against it. Priya, meanwhile, states she cannot confirm the number of people in the room. Considering their positions and the orientation of the cube, what can each person see and why is Priya unable to confirm the number of people in the room?
Since Keiji stands to the north of the cube and faces south, he cannot see Nia who is directly across from him because the cube obstructs his direct line of sight. The cube's opacity prevents Keiji from seeing through it to the other side. Keiji's view is limited to the north face of the cube and anything else in his peripheral vision that isn't obscured by the cube's presence.

Nia, who stands to the south of the cube and faces northwards, can see Keiji because there is a direct line of sight between them with the cube to either one's left or right side. She can observe his colorful shirt because the cube does not block her view from her vantage point. The cube would only prevent her from seeing anything directly behind it relative to her position.

Olamide, positioned to the east of the cube facing westwards, describes the cube's west face and the items placed there. This indicates that there is no obstruction blocking his view of the west face and anything immediately adjacent to the cube on that side. Since Priya is on the west facing eastwards, Olamide cannot see Priya, because she is blocked from his view by the cube. Likewise, Olamide is also blocked from Priya's direct line of sight.

Priya, who is on the west side of the cube facing east, states she cannot confirm the number of people in the room. This is because the cube blocks her view of Keiji and Olamide who are on the north and east sides of the cube, respectively. Priya can see Nia directly across from her, but without being able to see Keiji or Olamide, her view is insufficient to confirm the presence of all four people in the room. 

Since each person is standing around the cube and facing the center, they can only see the person directly across from them with the exception of Keiji, who is facing the cube directly, and thus, cannot see anyone else. The opaque nature of the cube, along with its placement and the orientation of the individuals, defines the visibility lines and thereby determines that Priya, who only has a direct line of sight to Nia, cannot visually confirm the total number of occupants in the room.