After all these images are sent to Lester, they are free to exit the casino. There are many bulb-shaped security cameras located on the ceiling of the main lobby. The quickest way to do this is to photograph the guard standing next to the cashier booth, and the keypad located behind him. Lester will tell them to send him images of a security guard, a keypad, and a security camera. Once the image of the main entrance is sent to Lester, they need to enter the casino. At this point, they can choose to send an image of the valet as well, which acts as an optional objective.
The player is tasked with going to the casino, where they first need to photograph the main entrance and send the image to Lester. The various points of interest the player photographs will determine the choice of entry/exit points, as well as other possibilities later in the preparation stage of the heist.
This mission is the first preparation needed for the Diamond Casino Heist.