In a large public park in the centre of a busy city, three friends; Jia, Kofi, and Marcellus, are playing a game of hide and seek. Jia is currently 'it' and is counting at a large oak tree with its sprawling branches widely spread, offering a good hiding spot. This tree is situated near a small, clear pond that reflects the surrounding scenery. Kofi decides to hide behind a cluster of bushes which is to the east of the oak tree, and these bushes provide adequate cover from Jia's field of vision as she counts facing the tree. Marcellus, on the other hand, finds a curious spot to hide: he climbs up another tree directly to the south of the one Jia is counting at. This tree is exceptionally tall, so he can see over the top of the oak tree where Jia is. Strategically, it seems like a good hiding spot because Jia would not expect someone to be above her eye level when she turns around to seek.

As the rusty leaves crunch under Jia's feet, she finishes counting and turns to her left, away from both her friends' hiding places, looking towards the north of the park where the meadow stretches out invitingly. Jia then takes systematic turns, scanning each direction. When she faces the direction of the pond, which is west, she pauses to admire the way the sunlight sparkles on its surface. Continuing her search, she goes to the east, inspecting the edge of the bushes where Kofi is hiding. Without spotting him yet, she finally turns to look in the southern direction. The question arises: throughout her initial search before wandering too far from the oak tree, from which positions will Jia be able to see her friends based on the spatial setup of the park and what can each friend see from their hiding spots?
When Jia finishes counting and turns northward, neither Kofi nor Marcellus can be seen. Kofi is behind the bushes to the east, and these bushes are out of Jia's line of sight because she is focused on the meadow to the north. Marcellus is to the south, directly behind her, and given that Jia is looking north, he also remains unseen. Marcellus, situated in his elevated hiding spot, can see Jia at the base of the oak tree as he is facing her direction from his treetop hiding spot to the south. 

As Jia turns westward to admire the pond, her line of sight crosses the open spaces of the park, but Kofi is still obscured by the bushes and remains out of sight since the bushes are to the east. From Marcellus's point of view, looking down from the southern tree, he has a clear vantage point and can observe Jia gazing toward the pond. Since Kofi is hiding to the east and Jia is looking west, Kofi can see Jia's side profile or back as she is not facing his direction.

When Jia turns eastwards to scan the bushy area, there is a chance she will see Kofi if she looks closely enough, given that Kofi is directly in her line of sight, behind the bushes. Kofi, on the other hand, has a risk of being discovered since he will see Jia approaching his hideout and may anticipate her gaze penetrating through his leafy veil. Marcellus, however, still remains unseen, even though he can see Jia searching around the bushes from his aerial position--he has the advantage of height which keeps him out of her immediate visual sphere.

Finally, when Jia turns to the south, she might think to look up, as an efficient seeker would consider all possible angles. If she does so, she might catch a glimpse of Marcellus perched in the tall tree. Marcellus, from his point of view, would see Jia looking around, and possibly looking up toward him. Whether or not Jia spots him depends on her attentiveness to positions above the normal eye level as most people do not instinctively look upwards when searching for someone at ground level. Kofi remains out of sight to Jia as the southward gaze does not include the eastward bushes where Kofi is hiding. From Kofi's perspective, while Jia is scanning to the south, he remains secure in his leafy enclave, with Jia's attention turned away from him.