In the first one, if you look closely, you can see a brown deer (mine) sleeping by the base of the tree in the background. Saosin and Ravyn are sitting on top of the Crying Idol, and Saosin's head is covering my deer's head and pictogram. My camera just happened to line up correctly to get them in a closeup.
You can do this with your own deer and another deer standing in a high place, such as the rocks on the playground, if you walk away from them with your camera towards the high point.
You can also glitch the camera into taking a closeup of your own deer. I'll see if I can find the video about that, if someone doesn't beat me to it. Here's a video: [link]

To remove the deer from the camera view, you have to alter your game's files. You have to be careful not to mess them up, or you will need to re-download the game. I'll see if I can hunt down the link that explains that, too. Read the comments here: [link]