There's a saying, "ask 4 geologists about a geological feature and you'll get 5 or 6 answers, maybe more".
My interpretation of what you have highlighted is not a rock arch - an arched rock formation created by erosion or other means. Instead, it is a rock that has been ejected from a crater during a meteorite impact.
During the impact phase, the rock has fractured in a way to give a curved surface to one of its sides and a flat surface on the other side. After ejection from the crater, the rock flew and possibly rolled, but landed with the flat side up and the curved side down.