Orkut introduced a light version for those who are accessing it from low bandwidth Internet connection.
This is too light and loading very fast, this will display a small image instead of photos, and clicking on that will display the actual photo. Also the updates and other things will also hide images.
You can activate or deactivate this from your settings http://www.orkut.co.in/GeneralSettings.aspx
If you activate the low bandwidth version of Orkut that will be shown as the basic Orkut theme to others (If you activated some Orkut theme, that will not be shown to others). When you move back to normal version, that will activate the theme you activated earlier.