Once you've created and saved a gallery, you and your customers are able to share it directly through Facebook or Twitter via the icons at the top of the page.
On a gallery page, click on the chain link icon in the top right of the image. This will open in a new tab and give you and your visitors the direct URL link to share the image and options to share to facebook or twitter. Clicking on the image will open up all images as a slideshow.
You and your visitors can view GIFs by clicking on the chain link icon in the top right of the image. This opens the GIF in a new tab in your browser and allow it to play.