[Lokibob]

All 4 images are where NASA has used the microscopic imager and pressed down the soil. After the imager does its job, they take another picture of the soil impressions.

On a couple of them, you can see the impression of a phillips screw, and on one, a slotted screw.

Mars is still a desert.

[djf]

The first pic is an object, not an impression. There's too much color difference and uniformity for it to be an impression. Pluss, you can plainly make out where it is starting to be covered by the sand, and you can see individual sand grains on the surface. The second pic very well might be an impression. But given that the first pic even exists, it almost looks like the second is a picture of whatever was under the first picture.
The last two are new today. They look very ancient to me.