Diamond object seen near Stevens Trail Auburn, CA

Around 11am on popular hiking trail in Auburn, CA, my group and I stopped about a mile down the trail to rest and take pictures at a lookout point. We took pictures of each other in yoga poses, and when we looked at our photos we noticed something in only one of the photos taken seconds after many others. It appears to be a large diamond shaped object with two narrow shapes protruding from the bottom, and when zooming in it appears to have a metallic shine reflecting light from the sun. We looked around when we noticed the object in the picture for anything that could have created that shape and there was not a single object in the sky. Had we not been taking pictures at that vantage point we would most likely never have seen anything flying by as the trees and hillsides provide coverage for a good portion of the hike.