How to optimize your NextGEN galleries with ShortPixel Image Optimizer
When you upload an image directly to a NextGEN gallery, you may notice that it does not get uploaded to the default uploads folder. That's why, by default, ShortPixel Image Optimizer (SPIO) will not optimize images uploaded to galleries via NextGEN.
To allow the plugin to optimize the NextGEN Gallery images, you need to enable " NextGen" option in our plugin settings (Settings > ShortPixel > Advanced). This option will add all your current NextGEN galleries to the Custom media folders list, and will also optimize all the future galleries and images.