Probably because phone cameras do various types of processing that varies based on manufacturer. My guess is that the preview you see before you take the image is both lower fidelity (to update it in real time, as it is effectively live video), and uses less intense processing. A lower res image often makes people look more attractive by hiding skin blemishes, while less intensive processing would likely further smooth over details you might not otherwise like.
If you want to take a good selfie with your phone, treat the preview as nothing more than a viewfinder for getting proper framing. Like people using more advanced cameras, take test shots to get a sense for what the lighting (and in this case image processing) will actually look like. As you take more pictures, you’ll get a better sense for how the camera works in different conditions. Once you become proficient, you’ll be able to accurately predict what the image will look like before the picture is taken.
Why does it always look fine until the instant I press the button 😭
Probably because phone cameras do various types of processing that varies based on manufacturer. My guess is that the preview you see before you take the image is both lower fidelity (to update it in real time, as it is effectively live video), and uses less intense processing. A lower res image often makes people look more attractive by hiding skin blemishes, while less intensive processing would likely further smooth over details you might not otherwise like.
If you want to take a good selfie with your phone, treat the preview as nothing more than a viewfinder for getting proper framing. Like people using more advanced cameras, take test shots to get a sense for what the lighting (and in this case image processing) will actually look like. As you take more pictures, you’ll get a better sense for how the camera works in different conditions. Once you become proficient, you’ll be able to accurately predict what the image will look like before the picture is taken.