This is a fascinating picture of Mars. The water, or liquid, appears frozen. I presume it is water or ice.
I am thinking from the picture it is ice. But what makes me think it might not be is the depth of the water. If you look at the shoreline or edge of the land, there is a definite edge where the sold turns flat and starts to show receding depth. Ice generally does not do that. Ice tends to not be able to be seen through.
Ice tends to gather dust, snow, or whatever. But in this picture there is the rock-line, a shoreline, and then depths as the rock disappears under the flat surface. There is silt brought down from higher levels and these are seen as furrows in the sand or fines under the water. This rippling of the water bed indicates water flow.
There is an island. There are all the characteristics of a delta or small inlet.
The only thing that is interesting and perplexing is this: if this is what it appears, why is there no life developed? Mars does get above zero around the equator. Maybe it reaches 12 degrees in the summer. If there is this much water, and it exists, why no green stuff?