one more observation 🙂
When I select a variant main image stays as it was but when I move mouse over it, it zooms correct image (as it would be swapped already)
see video: https://gyazo.com/eada0afa068a0ba317390498a8a08bda
First, I selected a blue colour, main image stays with both colours, moved mouse over image and zoom was showing blue colour only.
Then, I selected ping and moved mouse over main image .. saw pink image 🙂
So seems that we have a problem only with main image display.