If a gallery has many images, and the viewer doesn't want to manually click on each one to download, then he can use DpiApp's built-in ZIP feature to download a collection of images in one click.
If you need to enable downloading ZIP for your viewers, it's as simple as clicking a toggle button. First, go to the gallery you want to generate a ZIP with. Second, click the 'gear' button to switch to the 'Gallery Settings' tab, you can then toggle the 'ZIP Download' item to 'On', and your ZIP is ready!
After you set the ZIP Download item to 'On', the viewers who have this gallery's share link will be able to see a DOWNLOAD ZIP button on their side, they can then click the button to download a ZIP file containing all your images in this gallery.
It depends. If you have enabled 'Watermark Mode' or 'Low Res Mode', then the containing images in the ZIP file will also be adjusted to your watermark and Low-Res settings. If you are providing your original images in the share link, then the images will also be your original ones in the ZIP file.