These are Night Vision Assist Indicator symbols. They are an image inside the somewhat familiar triangle. Those images are either a running deer or a walking man and are meant to indicate either a wild animal or a pedestrian has been detected. They appear in red only.
An infrared camera is used to detect the presence of a warm blooded animal or person. The system is dependent on a temperature differential and becomes unusable above about 75 degrees F. The system is deactivated in these conditions as well as in daylight.