Many slopes in the middle latitudes of Mars show icy flows or glaciers. The region shown here, in the south-facing slope of a crater, is unusual because the flows have bright highlights.
The color and brightness variations are likely due to surface coatings of bright dust and dark sand. There is no evidence that these flows are currently active, but they may have been active only millions of years ago. These flows may well contain ice today in their interiors, as confirmed in places by the subsurface radar experiment on MRO. [More at link]