That pose is a rattler ready to strike.Once they coil they mean business. They would prefer to run away as they are not aggresive by nature and much more defensive in general.I did have a baby rattler charge me which was very unusual in my experience.I saw what I thought was a large lizard slither under my trash can and I just had a "feeling" I should check it out and as I rolled the trash can out of the way he charged at my feet.As I backed up he kept coming at me.Usually they take that defensive coiled pose and strike only if you move towards them but never come at you and keep coming.
