What's the blip today-Jim?

All things being equal, and my powers of deduction honed to the proverbial needle point- these two guys are professionals. Having already removed several bags of rubbish from out of the vista, they were biding their time waiting to take a shot of the street.
I take it, the photograph was for a "now and then" feature, since they kept referring back to a snapshot they had. If only they had come yesterday, when they would have had the street practically to themselves.