The mere exposure effect is "a phenomenon in which repeated exposure to a stimulus makes us more likely to feel favorably toward it". One example of the mere exposure effect is that a person tends to prefer a picture of themself that is a mirror image over the original image as taken by a photographer. This probably occurs because you are more accustomed to seeing yourself in the mirror every day, so you display a preference to it over a normal photographic image. This phenomenon is depicted in the video below. 5 couples were asked to participate in this study; each of them had their pictures taken and were asked to choose which picture they liked better, the original or the mirror image of that same photo. 60% chose the mirror image of themselves, some claiming that the light was better, they looked slimmer, or they looked less "wonky" (whatever that means). 90% picked the normal photos of their partners, complying with the mere exposure effect. Bear in mind that these researchers don't specify whether these findings are drawn solely from this experiment with 10 people, or from a larger sample size. Of course, if the results are only based off of 10 participants, we can't be too wowed with the findings. Ok, so the mere exposure effect makes sense, you prefer the picture of yourself that you see more often, but why did the other 40% chose the normal image of themselves, and why might the 10% of partners prefer the mirrored image of their partner? Perhaps the subjects preferred the normal picture of themselves because it was different. If you're used to seeing yourself one way in the mirror every day, then a new perspective could make you feel more confident about your looks. Also, one of the participants told their partner that it was hard to tell a difference because her face is so symmetrical. This could also be a clue as to why the certain percentages didn't comply with the mere exposure effect. Symmetrical faces tend to be perceived as more attractive, so maybe the more attractive a person is, the harder it will be to decipher between mirror and original pictures of them.
Heres the video: theres lots of British people in it, which automatically makes it more interesting. Also, basically stop watching after like 8 minutes, unless you want to see a skinny kid's head pasted on someone else's body. It's ok if you do.