Images to google photos

Hello, i just saw that google is indexing images from my website but mostly only those that are maximum 5 days old. Any other image that appears is from shared links. Directly from my site isn’t many, and this is bad because i don’t filling up google photos so it can spread my website to more viewers. How to fix this?

For example if i search “playsiders” and go to google photos mostly only those that are at max 5 days old appears directly from the site.

The page I need help with: [log in to see the link]