Sometimes having moved from the Midwest to the East Coast feels a little like having moved to a foreign country. I am going to guess that this thing is for a crossing guard, and that there are manual traffic light overrides inside. Back in Kansas school kids (like other pedestrians) are just on their own. Result: parents frequently drive their kids to school even if it's just a few blocks, and schools are hotspots of bad air quality.
https://www.google.com/maps/@39.9503865,-75.048869,3a,64.4y,6.74h,80.55t/data=!3m6!1e1!3m4!1sfGo8CsvBZs4_7CIiPyhPKg!2e0!7i13312!8i6656