Focus and exposure are maintained where the blue AF point is displayed while you press the shutter button halfway. This helps you avoid missing shots of subjects in motion.
Enable Helps avoid missing sudden photo opportunities, because the camera constantly focuses on subjects until you press the shutter button halfway. Disable Conserves battery power, because the camera does not focus constantly. However, this may delay focusing.
Reducing Red-Eye To help prevent red-eye, the camera can illuminate the red-eye reduction lamp before firing the flash in low-light shots. 1 [Red-eye lamp]
For assistance with Bluetooth pairing between the camera and a smartphone, please see this article: https://support.usa.canon.com/infocenter/index?page=content&id=ART173357