Dear Sir/Madam,
In the latest update(s) of Powerpoint for iOS there is bug which distorts some, not all, inserted pictures (compressing them in one of the two dimensions). Please correct this as quickly as possible. The same presentation looks perfect using both the latest macOS Sierra or Windows 7 versions of PowerPoint. Luckily, Keynote has become so good in opening PowerPoint files both on Mac, iPhone or iPad, which helped me out temporarily (until the bug is being fixed).
Regards,
Lennart