Complex sentence: As the observer explores the environment, her relation to these angles change, and thus the appearance of the environment changes; objects appear to grow larger or smaller depending on whether the observer moves towards or away from the object, though the objective object remains unchanging.
Split into simpler sentences: As the observer explores the environment, her relation to these angles change, and thus the appearance of the environment changes. For example, objects appear to grow larger or smaller depending on whether the observer moves towards or away from the object, though the objective size of the object remains unchanging.