WordPress.org

Why can't I change which thumbnail is used?

While the plugin will show thumbnails and will not break in WordPress 2.5, the ability to order the Gallery images was not added until 2.6.

Will this plugin work for images not uploaded through WordPress?

Short answer: no. This plugin relies on the way images are attached to a particular post when they are uploaded through WordPress. Images hotlinked from other sites (or even linked to a place on your own server not controlled by WordPress) are not tied to the post as attachments in the WordPress database.

Some of my images are just image links, some are uploaded through WordPress. Will this plugin break on my site?

No, but the plugin will only show thumbnails for images uploaded through WordPress. For posts with no WordPress uploaded images, no thumbnail will appear.

How does Ordered Thumbnails work?

This plugin works by first looking for any attachments in the wp_posts database table that have a post_parent ID that matches the current post and as a second step for posts with multiple image attachments, returning the attachment with its menu_order field set to "1". If no image attachments match the current post ID, the plugin returns "false".