You really shouldn't take selfies from a low angle -- it could lead to unflattering images that emphasize double chins, chubby cheeks and big nostrils. That is, unless you're the Curiosity rover, because it still looks good despite showing its belly in the photo above. This is definitely not the rover's first self-portrait, but it's the first one wherein the camera was positioned lower than its body. The image is a composite of 92 photos taken by the Mars Hand Lens Imager (MAHLI) on August 5th as the rover was facing northeast, with Mt. Sharp and the Gale crater visible in the background.
MAHLI is mounted on Curiosity's robotic arm, which is hidden from the final pic, thanks to its clever positioning. By the way, the photos were captured when the arm reached down to drill into a Martian rock called "Buckskin." You can see a wider view of the selfie below: the gray areas represent some of the powdered samples the rover collected from the rock for testing.
[Image credit: NASA/JPL-Caltech/MSSS]