Google Translate's Safe Mode

Google Translate has a new feature called Safe Mode, but it's not clear what it does. It's only for page translation and Google shows the following message: "Translated in Safe Mode. This may cause problems with some websites, especially those that use plugins like Flash. Click here to disable Safe Mode".

Google uses the "sandbox" parameter to enable the Safe Mode, so you can try it by adding "&sandbox=1" to any Google Translate URL. Here's an example for El Pais, a Spanish news site. When using the Safe Mode, the site redirects to the US version, but that doesn't happen when using the regular mode if you're not in the US.

Maybe the Safe Mode is related to this security issue.