My guess is that this feature is for stealth gameplay reasons, and is expected to be used to see around corners like lean in first person shooters. Removing the reticule while it passes through the blind spot of Agent 47's head would made it harder to know where one's reticule will be when it reappeared on screen. The low Field of View in the aim modes makes the reticule crossover difficult to achieve, and my complaints were likely viewed as acceptable compromises.
Here, we see that the camera's upward pitch is locked even when the avatar walks up close with the camera in between him and the wall. As the avatar walks away, the camera slides down the wall, moving forward first and then down and back with each few steps forward. The motion is not elegant, but the movement is smooth. The bottom and middle right stills show the camera sliding across the floor and maintaining its maximum distance from the player. These still show the shortest possible distance between the camera and the avatar's feet.
Unlike many third person games, especially platformers, the avatar's feet are rarely on screen - only when the player pitches the camera downwards by a significant degree.
This makes some of the thinner walkways challenging to traverse, and the content shows that the developers were aware of this limitation. The Library in the mission Run For Your Life does incorporate a short traversal challenge, but the path is wide and forgiving, with no threats from above so the player can focus downwards and look at their feet.
Now that we have taken a look at the main gameplay camera, I will catalogue and describe the other cameras in this game in my final article about Hitman: Absolution.