Whacky image behaviour in mobile app

[rocketman]

When I display a list of thumbnails in a mobile app on a wi fi network everything appears as it should. When I display the same list whilst connecting over 3G, some of the images appear upside down.

In all cases the offending images were uploaded via the same mobile app using Picup on an iPhone or iPad. Not sure whether that has anything to do with it - might just be a strange coincidence.