The default 1.9 product magnifier is not initialising properly on page load. But does initialise when a thumbnail i.e.
.thumb-link is clicked.
I have done a diff on the difference between
.product-image and it's descendants before and after manual initialisation of the magnifier by virtue of clicking on a thumbnail.
The difference is the addition of
zoom-available to the
product-image class as well as
visible to the