I looked more closely when I saw that the "rock" had a face on it. Then I noticed it had legs.
From what I can tell, this is a Wolf Spider carrying an egg sack. Seems a strange time of the year for that; but then lots are things are happening at strange times this year.
I encouraged the spider onto a rock which I carefully moved to another part of the yard... away from the project. The last I saw, it was moving quickly for the shadows.
As for the project, this is what it looks like now.