On my WP site (which sells retail products), I have large images (up to 4000x4000 px) so people can zoom in. Unfortunately, when adding images to a page and using the Media Library, the images all load up at full quality (though resized down). This makes the Media Library page load up really slowly, and make my browser slow to a crawl. Why is it doing this? Why isn't the ML page using thumbnails? If I click on "Media" on the left admin menu, that list of images are proper thumbnails, but when adding media to a page, the list that comes up is using full quality images.
Is this a bug in WP?