Someone strolled around and dropped a squirt of glyphosate every few paces. That stuff has an area effect so it'll kill grass in a small radius, if they'd done the (apparently) obvious and sprayed a continuous stream to mark out the digits it'd have ended up as a big blobby mess. Whoever did this put some thought and planning into it.
But it's strange that all the dots appear to be the same size, so I'm guessing round object. Is it possible to go there with a round pick nick blanket and sit every day in the same spot until the grass die?
Wow, the parks police, the secret service, and the national guard. They must have consulted with the department of government efficiency on how to cost effectively investigate dead grass.
