Is it because of the "androgynous" tag? The "androgynous" tag refers to the character's physical traits and has nothing to do with some symbol in the background.
If that symbol wasn't there and you didn't look at the pixiv tags you simply wouldn't be able to tell his sex.
tinybrazilian said: yes it is a male because of the feet shape... hurg... very ugle feet :(
What? They're nice feet. Also, what's the tag for searching "feet" on Pixiv? I translated the word using an engine, but it doesn't really give me anything when I use it.