belief in the existence of a god or gods, especially belief in one god as creator of the universe, intervening in it and sustaining a personal relation to his creatures.
The book says god and theism is the belief of a god
a person who believes that nothing is known or can be known of the existence or nature of God or of anything beyond material phenomena; a person who claims neither faith nor disbelief in God.
The photo is showing that winds may exist and agnosticism is not knowing if a god exist that it may exist.