This image was targeted to cover part of a small “chaos” terrain, where there are lots of steep slopes.
A closeup shows a boulder or block casting a long shadow, at the end of a boulder trail down the slope, and we can see it moved from upper left to middle right. The trail has a odd repeating pattern, as if the boulder couldn't roll straight due to its shape.
The sun angle and shadow length indicate the boulder is about 6 meters high, whereas its width as seen from overhead is only about 3.5 meters, so indeed it has an irregular shape. Furthermore, it came to rest with its long axis pointed up.
This is a stereo pair with ESP_035700_1765.
Image credit: NASA/JPL/University of Arizona
Note: This boulder is located in Ophir Planum. For more information, see PIA18594: An Irregular, Upright Boulder on Mars and Tall Boulder Rolls Down Martian Hill, Lands Upright.