Should have been more like Gulliver's Travels....
In Gulliver's travels the main character Gulliver is tiny compared to the inhabitants of the first island he visits but the next island he visits he is the giant (or maybe it was the other way around) so you see 2 different perspectives.
A way to follow the literary device of "2 different perspectives" here would have been for her to break up with Mr Grey and a different billionaire falls in love with her and this one is a masochist instead of a sadist and she is the one who has to tie him up and whip him but he never hits her, kind of the opposite of Grey.
I think that would be more clever.