In product page to show at least few related items and to show to choose another category (collapsed option that is done at product list page).
From consumer experience if product is not what he is got interested and if there is not related items or option to go to product listing (categories) user will leave.
And big issue on mobile (tested at least on blackberry Z10 and torch 9810) when in mobile product page i press image, there is not option to close it (big image on black background, z10 even don't show image at the center)! if press back button, user redirects to product listing page. The same black screen on PC - without any close button (strangely showing "search" text on image top right corner- after click it act like pressing search button - anyway it's not closing that image and come back to product page).
Tested on Firefox 25.0.1 (for Ubuntu PC) as well.
It's very uncomfortable. There is a solution how to fix this image showing issue?