Can I lock specific photos in a page while working on other images from the same page?

This feature is currently not available however, you may use Ctrl+Click as an alternative. However some assets are 'locked', and cannot be moved or otherwise edited and photos used as a background cannot be moved, resized or deleted. 

For example : If you want to lock the quote and move the pictures together, this feature is not available in the software, however instead of moving it one by one, you can press Ctrl+Click on the images and move them together without affecting the next object on the page.