Someone told me, "your self-esteem is high to put your picture into a profile pic" i'm sorry to ask but what does that mean

A lot of people don't put their actual face in their profile pic, either due to preferences or because they don't like their face. The thing is that putting your actual face on your profile pic will expose your face to whoever sees your profile, so you'd have to have the confidence to show everyone on the internet your face like that. Personally, I don't put my face in my profile, because I don't like any pictures of my face. It's all relative to your own opinion though, so don't worry about it too much. Hope that helped somewhat.