There's quite a lot of suction created around the nacelle at high thrust, and the pressure differential is depressing the nacelle skin.

The aircraft has flown several sectors after the recent rotation to the Bahamas, and will have received turnround/transit checks, so either this isn't a problem, or isn't leaving any visible signs once the aircraft has completed a flight - unless of course it's indicative of an underlying structural failure in the nacelle which has yet to become fully apparent with the aircraft parked.