She agreed, reluctantly, to be tied up, but certainly did not agree to be photographed helpless and exposed. But when he produced the camera she wasn't in the best position to tell him 'no'. It was embarrassing, but as long as it was between them it was ONLY embarrassing, not mortifying.
"OK, OK, I deleted the picture," he said after she complained. She didn't really believe him, but what could she do? At least he probably wouldn't show it to his friends, or worse, put it on the Internet for a bunch of strangers to drool over. He wasn't a total douchebag.
A year later they broke up, and she said some pretty rude things in the process. She had forgotten all about the picture by then....