You can set from Hide My WP > Change Paths > WP Core Security > Hide WordPress Common Paths the extension files you want to hide on the old paths.
By default, the images are not included as it may affect the indexed Google images.
After you change the paths, it will take a while for Google and other search engines to index the new images URL.
If you still want to hide the old images, add this line in wp-config.php file
and you will see the images option in the Hide File Extentions list:
Select the Images and save the settings.