>>28996776 (OP)This was intentional. She knows she wasn't wearing a bra. She knows she wasn't wearing nipple guards or pasties. She knows she wasn't wearing anything else underneath. She knew where it was, where the limits of the covering were, where her exact nipples were located in relation to her clothing. She knew what her hands were doing. She knew what she was "risking".
That she goes on to "express" "shock" and "surprise" for nearly twelve entire seconds is exaggeration to the point of silliness. Genuine surprise has a micro-expression time limit of less than two seconds.
She was playing up for the camera. She knew she was recording.