I think the UI design is missing an opportunity with the status icons signifiers too. The blue cloud is excellent - it immediately conveys the concept that the file exists "in the cloud" and, in this context, the user will understand exactly what this implies (i.e. they need to be online to access it, and they do not have a copy cached locally). The green tick only implies an ambiguous "success" condition though, and given the other UX issues above, it's not intuitive exactly what has been successful. I can't think of a image as effective as the blue cloud, but if it was a green icon of a computer it would imply both success and the file being available locally, even it it didn't highlight the concept that the locally cached version is a copy of the original, not the original itself.