Reply #2: Notice the shadows extending over the right photo, but not the left.

[TexasObserver]

This allows us to infer correctly that the right photo of the Democratic event was taken early in the day, and the procession of attendees we see walking to the main area from the left also confirms it was early in the day.

The sun is directly overhead in the Beck photo, as the sun's muted reflection in the water demostrates.

Conclusion:

Beck used photos taken at much different times to deceive people. The shot of our event was early in the morning. The shot of his event was in midday, probably 5 hours later, at the peak of the event.