1. Scroll down the page to load all images.
2. Click on Pinterest Save Button.
Problem
Are you using Pinterest Save Button extension in your Chrome browser? Have you noticed that on some websites not all images are being loaded into a Pinterest sandbox?
The animated gif below shows the problem. The page includes 50 images, but only few appear when you click on Pinterest Save Button.

Explanation
Some modern browsers, including Chrome, have started to support image lazy loading natively. If an image class on a website includes loading="lazy"
parameter, the browser will load it only when the image will appear in the browser’s viewport.
In other words, the images you won’t see on a website will not be displayed in the Pinterest Save Button sandbox.
How to load all images to Pinterest Save Button
1. Scroll down to the very bottom of a page make all images appear in a viewport.
2. Click on Pinterest Save Button.
3. You can select up to 10 images to save to your Pinterest board.
4. If you want to save more images from the same webpage, simply use the Pinterest Save Button again. There is no need to scroll down the page again – all images are already loaded properly.