These painted rocks are near the sidewalk on Pershing Drive, on the west bank of the Naugatuck River. It's a desolate spot—the other side of the street has empty fields surrounded by cyclone fencing. No one ever seems to walk through here. My first thought was that this might be a school project, something serving as an outdoor activity, maybe in compensation for cancelled or virtual graduation ceremonies. It's that time of year, and the rocks weren't painted the last time I walked through here, not more than a month ago. The last rock seems to have a military theme though, so my first thought might be wrong.
I searched on "Ansonia painted rocks," and got two hits for Facebook pages which returned error messages, likely indicating pages for closed or invitation-only groups. So it's still a mystery.