Taken on November 20, 2016 by the High Resolution Imaging Science Experiment [HiRISE] camera on NASA's MRO, the photograph is constructed from the best image of Earth and the best image of the moon from four sets of images, which were acquired to calibrate HiRISE data. When the component images were taken, Mars was about 205 million kilometers [127 million miles] away from Earth.
In this image, the reddish feature near the middle of the face of Earth is Australia. Southeast Asia appears as the reddish area near the top, Antarctica is the bright blob at bottom-left. Other bright areas are clouds.
As NASA describes in it's Official website, the image combines two separate exposures. For presentation, the exposures were processed separately to optimize detail visible on both Earth and the moon. The moon is much darker than Earth and would barely be visible if shown at the same brightness scale as Earth. But the combined view retains the correct positions and sizes of the two bodies relative to each other.
You may have noticed that, in the photograph both Earth and moon appear closer than they actually are because, the observation was planned for a time at which the moon was almost directly behind Earth, from Mars' point of view, to see the Earth-facing side of the moon.
With HiRISE and five other instruments, the MRO has been investigating Mars since 2006. In 2007 HiRISE had also snapped a similar image, when Earth was 142 million kilometers [88 million miles] from Mars.
article reference:- nasa.gov & jpl.nasa.gov
image credit:- nasa/jpl-caltech/univ. of arizona