It could be a Silver Leghorn, but the body and tail feathers look too long for a Leghorn. I may be wrong. It could just have the wrong leg color, which is a common problem in hatchery stock.A silver phoenix would have dark slate legs. I first thought phoenix as well, but after more research it doesn't fit. So they only other I could think of was a silver leghorn, the color and body shape fits for a young leghorn pullet.