This is a known issue under investigation by our development team. It appears to be limited to Chrome in Windows 10. For your reference the ID of this issue is IGLOO-12408.
At this time, the best workaround is to either use an alternative browser or download the file in question to be able to use your workstation's programs to view the file if a larger view is needed.
I apologize for any inconvenience this may cause in the interim.