The following applies if the photo was taken in front of Chelsea Clinton’s apartment:
If the photo was taken at 3:30 or 4 in the afternoon as you suggest then the shadows would be cast in front of Clinton, not behind her. (Building are to the left of Clinton, which means she is facing southeast (there’s a park across the street). This is further confirmed by the direction of the parked cars, 26th St is one-way toward the southeast.)
Use the solar position calculator http://www.esrl.noaa.gov/gmd/grad/solcalc/azel.html Enter the location, date, and time, then click “calculate”. The azimuth is aprx 250°, which means sun rays will come from the southwest (unsurprisingly) and cast shadows to the northeast.
The street runs northwest to southeast. In the photo shadows are cast behind Clinton, toward the north-northwest. The photo could not have been taken at 3:30 or 4 in the afternoon.
Naturally, if the location is in error then none of this applies.
Technicalities aside, the photos and video, according to the events, would have had to have been taken before she went to the event, or after she was brought to the apt as they claimed, after collapsing at the event, and then recuperating for 90 minutes. So how to adjust all this? None of it makes sense.
Maggief posted a link to google map location of the apartment, and one can move the cursor around and see both the front and back of the apt building, down the streets, etc. It definitely is the location.