There are two pots at the street edge of my sidewalk, each containing a small juniper tree, and with lush annual flowers fountaining from the tree bases. The pots are enormous, and because they are filled with dirt and plants, they are too heavy for me to lift.

The pots basically work as bollards. Traffic calmers.

See, in my city neighborhood, people like to pull up partly onto the sidewalk. Sidewalks are not designed to support cars, so the pavement eventually cracks and sinks under the weight of the auto, and I don’t want to have to replace my sidewalk or any of the essential pipes beneath. So I stuck some pots out there, as a visual reminder to my neighbors to park better, and the project has been successful. Also, passersby compliment the plants. 

Yesterday, though, I suddenly noticed that one of the pots was facing the wrong direction, with the most flowery part facing the street. There was a little scattering of mulch to the right of the pot. 

Why did someone turn my pot around, and why only one of them?

• Did someone try to steal the plant, only to realize it was too heavy, and then carefully replace it, but facing the other direction, and with the bricks underneath all still in their proper positions, aligned with the marks they make on the pavement?
• Did someone want to park on my neighbor’s sidewalk, moving the plant and the bricks underneath, and then putting it back, backwards? This would take at least two people, so I would assume a contractor with an assistant.
• Did a car back into the pot and knock it over? Then did the driver (and a passenger, I assume) see what they had done, and remorsefully replace it, unlike any Philadelphia driver I have ever known? Hell, the time an eighteen-wheeler caromed through our street sideswiping every other car, the driver just got to the end of the block and kept going, even though every camera on the block had recorded him doing it, and even though someone posted a dash-cam snippet of the event on Reddit. Also, the plastic would at least be dented in that case. It’s not.
• Did some passing group of children decide to play an almost unnoticeable prank on me, for no discernible reason? The kids in my neighborhood are much more likely to rip out the flowers, ram the pot with a scooter, or batter it with a metal pipe they found and decided to put to good purpose. I mean, I once saw three of them on my camera, lying on their backs trying to knock down my front stoop wall with their feet because they could see cracks in the wall and it struck them as a great idea to try to crumble the whole thing.  (They didn’t succeed.)
• Did a pair of cultured passersby decide that the flowers should be facing the street instead of my front step, and correct my design flaw? I say a pair because that thing is, as I have noted, heavy.

I saw no contractor even though I was home much of the day, but that scenario sounds the most plausible.