Imagine a serene beach on a clear day where two friends, Isra and Dakarai, decide to spend their afternoon. As they arrive, they notice the beach is bordered by a perfectly straight shoreline extending in both directions as far as the eye can see. Isra, who is particularly keen on exploring, suggests they should conduct an experiment to understand how their perception changes as they wade into the water. Dakarai agrees, intrigued by the idea.

They mark a starting spot on the sand where the waves gently lap at the shore. Isra and Dakarai both have sticks that they plant vertically into the ground at the starting spot. The sticks are of equal height, which they can just look over when standing right up against them. They agree Isra will stay at the shore, while Dakarai will wade into the water at a perpendicular angle to the shoreline. The beach slopes gently and uniformly into the ocean, so Dakarai expects the water to rise consistently on his body as he walks in.

As Dakarai wades deeper, Isra is tasked with observing what happens to Dakarai's visibility relative to the stick at the shore. She needs to take note of which parts of Dakarai's body are hidden by the water at various distances. Furthermore, they want to test if there is any difference in perception if Dakarai turns sideways compared to facing Isra straight on while moving into the water.

Knowing that they are both of the same height and that the sticks are as tall as they are, Isra and Dakarai wonder what changes Isra would observe from her vantage point at the starting position on the shore if Dakarai keeps wading deeper into the water until the water reaches his shoulders. They are curious about Isra's perspective regardless of whether Dakarai is facing her or turned sideways. What will Isra report seeing as Dakarai wades deeper into the water, and will her observations change based on Dakarai's orientation?
As Dakarai walks away from Isra and into the water, the water level rises against his body. Depending upon the depth and his distance from the shore, different parts of Dakarai's body will be obscured from Isra's view by the water's surface. Initially, as Dakarai starts to wade into the water, only the lower parts of his legs are covered. With every step he takes, more of his body will be submerged, and this progression is steady due to the gentle and uniform slope of the beach. 

From Isra's perspective at the starting position, she can see Dakarai's entire body above the apparent water line. She watches as the water gradually covers Dakarai's ankles, then calves, and up to his knees. Because the slope of the beach is consistent, the rate at which Dakarai's body is obscured is uniform. Isra, taking note of each change, would observe that once the water rises to Dakarai's waist, she will only see the upper half of his body.

Let's consider the instance when Dakarai turns sideways to Isra. When Dakarai is facing her directly, Isra sees his front or back being covered uniformly by the water. However, when he turns sideways, the width of his body that Isra can see becomes thinner as the water hides more of him from her perspective. It would seem to Isra as if Dakarai's body is more slender when viewed from the side than when he is facing her because of the water obscuring the width of his body.

As Dakarai keeps walking and the water rises to his chest and then to his shoulders, Isra's view from the shore will continuously decrease. When the water reaches his shoulders, Isra will only be able to see his neck and head above the water's surface. The rest of his body will be hidden. 

The orientation of Dakarai affects the perception of how much of him is visible above the water due to the change in the body profile that Isra can see. Regardless of Dakarai's orientation, the parts of his body that are submerged remain constant--water relative to his body does not change. However, what changes is the apparent thickness of Dakarai's body above the water level as he rotates. When he is facing Isra directly, she sees more of his body than when he turns sideways, resulting in a slimmer profile being visible.

If Dakarai continued to wade deeper until the water level reached just below his chin, the majority of his body would be submerged, and Isra would be able to see just his neck and head. No matter his orientation, submerged portions remain hidden and the visible sections are consistently above the waterline. The water provides a horizontal line across Dakarai's body from Isra's horizontal vantage point, masking everything below that line from her view.