Article + Slideshow
It makes no sense to have an image gallery with a thumbnail grid to open the large images on a responsive page.
Think of all the extra images required and the amount of scrolling required by phone users.
The item above needs just a single lazy loaded image to launch the slideshow and provides a text block for the gallery name and also a description for the visitors and the search engines.
Images
The slideshow inserts a full size and a mobile size image for better download performance on phones.
Captions
The image caption can be aligned vertically at the top or bottom and horizontally at the left, center or right.
Lightbox
Action Tabs
The previous/next tabs are inserted halway up at the left and right.
The action tabs can be removed for all or some mobile devices by checking a box and setting a suitable breakpoint.
Overlay
The lightbox overlay has controls for the background color and its opacity. The close action tab is optional since it is not always required.