If you take a close look (as always, click to make bigger) you can see that the pole has been marked as #2. It is pretty small, and pretty high, and pretty hard to see... but there must be a reason for the identification.
Perhaps to help people remember what row they parked in, but there is really not that many rows.
Or maybe it is for maintenance purposes? "Joe, you need to replace the bulb on the north side of pole number 2."