Caption calculation has a somewhat complex logic on it and it lives in a theme function "_glightbox_formatter_get_caption", it would be more flexible if we had a service for it so anyone can really implement/decorate their own captions without adding too much burden to this module, i.e. if the video one I've implemented here https://www.drupal.org/project/glightbox_media_video/issues/3492655 📌 Allow caption to use title and description for remote video Active had to duplicate this code.
Active
1.0
Code
Hi pcambra, sounds good to me, I will have a look this and move calculation of caption in separate class/service. This GLightbox module was forked from Colorbox module, which is rewritten from D7 module. So it's old fashion legacy.