We often look better in selfies than in photos taken by others due to a combination of factors: familiarity, angle, and control.
The Familiarity Factor
We are accustomed to seeing our reflection in mirrors and selfies, which presents a reversed image of our face. This reversed image is what we consider our "normal" appearance. When we see ourselves in an unreversed photograph, the slight asymmetries in our face (which are barely noticeable in the mirror) become more apparent and can appear unfamiliar or even unflattering. This is supported by numerous sources, such as this Quora discussion: Why is it that I look pretty in selfies and mirrors but not when someone else takes my photos?. Reddit users also frequently note this phenomenon: Genuine question — does anyone else feel like they look GOOD in ....
Angle and Lighting
Selfies allow for precise control over angle and lighting. We instinctively position ourselves and the camera to minimize perceived flaws and highlight favorable features. As one source notes, "People tend to look better in photos when their body and sometimes face is at an angle and not straight on facing the camera." [Source: Jan 4, 2018]. This subtle angling can create a more flattering perspective. Furthermore, we often take selfies in environments with lighting we've carefully selected to be flattering.
The Control Factor
Taking selfies grants complete control over the final image. We can retake photos until we find one we are satisfied with, selecting the most flattering angle, expression, and lighting. This iterative process inevitably leads to a more aesthetically pleasing outcome compared to spontaneous photos taken by others. The Science Behind the Selfie (No, You Don't Really Look Like That ...) touches on the impact of this control in shaping our perceived image.
Camera Lens Effects
Different camera lenses and focal lengths affect how our faces appear in photographs. Ever think you look 'better' in a selfie v a pic someone's taken? mentions that these can distort facial features, leading to variations in how we are perceived in different images.
