I am a woman who used dating apps for years (and eventually met my husband on one) and this is exactly the advice that I would give anyone using a dating app. These 4 pictures are enough to give someone a quick window into your looks/personality while also giving them something to ask about or bring up in conversation. It can feel vain or odd to post pictures of yourself but it's really a kindness to the person on the other side of the app that makes initial contact much less stressful!