The reason it is blasphemous is that the cross and Greek lettering in the nimbus are used only in icons of Christ, 'ο ων, "the existing one" is the Greek version of the name God gives to Moses during his encounter with God in the burning bush, and is used to depict the fact of Jesus's Divinity. However much tumblindice may think that Obama regards himself as God, or wants to be worshipped in place of God, or is an antichrist, it is offensive to traditional Christians to communicate that belief with a blasphemous picture.
Please remove the picture, or if need be the entire post. tumblindice is welcomed to repost the PeoplesCube graphic of Obama saying stupid things about Jesus and Joseph if he really thinks it contributes to the discussion.