Without Internet connection, overview page stays empty

[mauritsvanrees]

• Start up a local Plone instance with plone.distribution.
• Go to localhost:8080
• All is fine.
• Now switch off Wifi or other internet connection.
• Reload the page.
• You just see "Loading...":

Switch wifi on again, and the distribution images appear, without needing to reload the page.

I put a breakpoint in DistributionImageView.publishTraverse. This only got triggered after turning on the wifi. So I don't quite know what it is doing before that.