Hello,
when you see only the loading image, it means the content was not loaded. You can test it when ou add only simple content before the image (e.g. word "test"). You can extend the time out by this property:
Load delay and speed up resizing by:
Resize speed. If the main image is smaller, it also helps. The difference between content before and after is probably in the way how the browser loads the source. If the borwser does not download the full content of
Selected item transformation until the timeout, you only see the loading icon.
The layout of lightbox is stored in the full source code. If you didn't purchased it, you cannot access this code.
If you do not like the built-in lightbox, you can always integrate a 3rd party lightbox and use only data from Kentico to provide it to that control. An example:
Integrating 3rd party components in Kentico CMS.
Best regards,
Helena Grulichova