The first picture is after they poured the footings and filled the area with gravel. This occurred on 6/21.
This 2nd picture shows the foundation walls being held up with the forms used to mold the concrete. You can see the forms in the first picture before they were used. This occurred between 6/22 and 6/27 with the picture being taken on 6/26.
The last picture of the home site was taken after the forms had been removed on 6/28. You can see on the right side some Styrofoam insulation. This insulation runs down the left side of the foundation as well.