Australian singer Samantha Sang had only one big hit in the US, and it was a huge one. Then again, it was written by two of the Bee Gees, who were absolutely HOT in the late 70's.
"Emotion", co-written by Barry & Robin Gibb, with Barry on backing vocals, peaked at #3 in the winter of 1978. 23 years later, Destiny's Child covered "Emotion", but only got as far as #10 on the Hot 100. Maybe the fact that the original was still getting decent airplay on oldies channels had something to do with that, I suppose.
The multiple images of Sang in the video is an old gimmick used by movie legend Buster Keaton, then co-opted in the 80's by Paul McCartney (at least twice) and Phil Collins, among others.