Image manipulation in research works has become an area of great concern. Journal editorial offices are increasingly investing time and effort (not to mention using expensive tools) to look at submitted images, much as the use of plagiarism tools is becoming standard for text. While digital tools have made it trivial to optimize your data images to better emphasize your results, there is a line where that manipulation becomes an intent to deceive the viewer.
Thinking about this, I was reminded of the short video below. Just as every scientist wants you to believe that their conclusions are definitive, so every advertiser wants you to believe that their food is delicious and a host of visual tricks have been established to visually enhance their appearance. Bon apétit!