Great question, thanks for posting. Let me see if there is a list of the various symbols and what they all reference.
Hi Jamie: That symbol is used to indicate that the attachment is a ServiceMax SmartDoc - a PDF rendering of the service report the customer signed.
Hi Robert, Whenever Smart Doc / Output Document is created on your device and is not yet synced, it will be displayed with an atom symbol. Once it is synced, this is replaced with a cloud symbol which indicates that it has to be downloaded again. Once the document is downloaded (by tapping the symbol), the cloud symbol is replaced with the PDF symbol. Online help will be updated to include this information more explicitly.