You are asking me why I can't write plainly, but I believe you're confusing me for the author, but I'll answer you anyways. "Plain" language removes nuance. Example: "She sat on the chair". The number of ways that action can be described are as innumerable as the ways it can be done, and then some - as different people may describe an act in different ways. Communication in all forms is lossy, but you can convey more than just direct ideas by adding subtext or using language that draws the reader to make comparisons new comparisons. Perhaps the author used gaze to anthropomorphize the camera to add on the layer of judgement or shame that the camera conveys, perhaps to an employee that is not trusted to manage a till.