The image is very detailed because the Dawn detector is in a very low orbit when taking a photo. They showcase some of the large craters on Ceres and the peculiar features that have yet to be explained.
As NASA explained, since the Dawn probe reached this dwarf planet, the Dawn was only 240 miles closest to Ceres. When the photo was taken, the Dawn Detector swept past 22 miles from the ground of Ceres. This incredibly close range allows Dawn to take a more detailed picture of Ceres, which contains some very amazing details.
“Getting these spectacular photos is one of the biggest challenges of Dawn's extraordinary alien adventure, and the results are better than we expected,” explains Marc Rayman, chief engineer and project manager at the Ceres mission. “Dawn is like a master artist. In the close-up image of Ceres, it adds a lot of detail to this extraordinary beauty.”
The mysterious highlights on Ceres have long puzzled scientists. Scientists now believe that these highlights are large carbonate deposits that are exposed due to geological activity. How these highlights are formed remains a topic of debate, but these new images will provide scientists with more information to form theories.
"The first batch of Ceres images won by Dawn included a single, dazzling highlight," said Carol Raymond, Principal Investigator of JPL's Dawn project, in a statement. "It will be exciting to uncover the nature and history of this fascinating dwarf planet during the long stay of Dawn in Ceres, especially Dawn will provide a wealth of new data to test these theories."