Google translate can only translate text that is on the page, when the page loads.
This is not really the case with Hotspots. We only have parts of the application on the page. Once the page is loaded we do ajax requests to get the data. This "loading data" window is created through javascript and that is why google translate can't tranlsate it - it has not idea that such window exist at all.
With that said - you can only translate that information through joomla. We use the multilingual function in joomla for translations. So if you switch your language to spanish - you should see a spanish translation for this text.
If you look into the source code of your page you will see something like this:
Hotspots.Localization = {"directions":"Route berechnen","getDirections":"Route berechnen","zoom":"Zoom","to":"nach",....
Google needs to translate this thing, but since it is all a javascript object google translate is not touching it as it might brake something...
Cheers,
Daniel