Yes, the mall also includes the public area shown on the chart. The public area was being used for other events on Saturday. The rally consumed much of the ticketed area - which can hold 240k according to the chart - but the portion of the ticketed area represented by the rectangular field remained largely unpopulated.
The rectangular field appears to be about 1/4 of the ticketed area, so it would seem fair to say that about 180k rally members were on the mall. I recognize that the event was dynamic - people were walking along Pennsylvania Avenue and coming and going all day - so the actual number of participants will be higher than the number on the mall at any given time. How much higher is anybody's guess, but I would think anyone who says the crowd was a couple of hundred thousand is not too far off.
Agreed.