said 9 months, 2 weeks ago:
Wordpress has a plug-in called lightbox. You might like that. You can ask it to operate on click on mouse over. Usually on click, and it will appear over the page and turn the background transparent grey. There are variations on this.
Meantime, a simple work-around is to have your image in your wordpress page be smaller than the full size image so that when it’s clicked, the full size image is what will come up on the new page.
Hope this helps.