The term 'lightbox' traditionally refers to an effect used in the visual arts where a translucent image is layered over a light source to create an amplified and enhanced appearance. Transposing this concept to the digital world, the 'Responsive Lightbox' plugin applies this technique to images or galleries within your WordPress site.

The backbone of this plugin is its ability to overlay the main content of the screen with an enlarged version of the image, while dimming out the rest. However, what differentiates 'Responsive Lightbox' from its contemporaries is its mobile responsiveness, offering a seamless experience across all devices. The images automatically scale, ensuring that they look just as pleasing on a mobile or tablet screen as they would on a desktop.

'Responsive Lightbox' provides multiple lightbox script options each with distinct animations and effects, thus giving a platter of possibilities for tailoring your image presentation. Further, it also facilitates automatic addition of lightbox to WordPress image galleries, image links, and even video links.

The plugin is not restricted to just images: it can also handle videos, iframes, and other links, widening the scope of what can be displayed in your lightbox view. It takes a step ahead by allowing users to navigate among the lightbox items via keyboard or touch gestures, all aiming to provide an engaging and immersive user experience.

This also comes with a simple back-end interface, making it easy for anyone to navigate and customize the settings. Not only does it provide a slew of generic configuration settings, but also accommodates several advanced settings to help you optimize the functioning of the plugin as per your needs. All in all, 'Responsive Lightbox' is an all-encompassing solution for image and media handling in WordPress, merging aesthetics with functionality in a balanced manner.