Anti-Sun is a star of darkness instead light, and coldness instead fire. It is also called Anti-matter Black Hole of Doom. While Sun brings life and joy to the creatures he illuminates, Anti-Sun just brings death and suffering to the Anti-Earthians.
As it absorbs light instead generating it, it is just impossible to take a picture of that horrible star. If you want to imagine it it is like a giant invisible hole in the space where you can not see light of stars. You can feel its presence... it is cold... it is an evil atmosphere. If you remain under its anti-light during a minute you will be filled of his evilness and darkness. Then you ruined soul will hate him, but the hatred will be tasty for your ruined soul so you will love him in a hateful way. Indeed, people of Anti-earth worship it as Bringer of Fear and Lord of Uneasiness.