Make sure you resize the photos to a reasonable size, around 100-300 KB would be good. The quota for this site is only 100MB, so uploading a photo of few MB is a bad idea.
If you're using linux you can resize a photo easily:
convert -resize 30% SANY0019.JPG SANY0019-small.JPGUpload the resized photos to this page, make sure the name is unique, if you have time, name them properly so it's easier to manage.
Go to the page your want to add photos to and edit it, from menu Insert > More Gadgets -> Add gadget by URL, enter this URL:
http://sites.google.com/site/ayuiorg/gadgets/images.xmlRemember it's http, not https
Copy the image URLs from photos page view links into imageN fields, empty imageN fields will be ignored.
Uncheck the checkboxes:
then click OK, save the page and you're done.