It could be from many different things I am sure. I know some photographers use magnifying glasses when inspecting prints while others will stand back several feet to try to take in more of the print to better evaluate the created impression. I am rapidly becoming of the opinion that it would be a matter of nicety to those who read the reviews if the methods used in arriving at their conclusions could be included with the results to better allow readers to conclude if it is something that could be important to them. Yes, there is a good deal of room for subjectivity in comparisons when there is nothing to weigh or measure. We do rely on objectivity from the observer. If the methods of comparison were also included it would mean that the testing ought to be reproducible by others with similar results. I'd expect some variation due to differences in keenness of sight, lighting condition, original exposure, gamut range of printer, etc but I wouldn't expect a factor of four.