Why men and women take selfies differently -- Quartz, 2017, 4:17 -- https://www.youtube.com/watch?v=jC6mR7g7ES4

An interesting example of how masculinity and femininity are found in taking selfies. Men look down at the camera (signaling dominance) while women look up to appeal to men. There's a brief discussion of online dating data as well. A downfall of this video is the interpretation based in evolutionary theory, rather than sociology.