The reason is that the screenshot of the app we uploaded is not used in the app. The solution is to set this as the startup welcome interface or replace it with a real app screenshot.
The original text is as follows:
Guideline 2.3.3 - Performance - Accurate Metadata
We noticed that your screenshots do not sufficiently reflect your app in use.
Specifically, your screenshots for iPad show your app in use in iPad.
Please see attached screenshots for details.
It would be appropriate to provide screenshots that reflect your app in use in iPad.
Next Steps
To resolve this issue, please revise your screenshots to ensure that they accurately reflect the app in use. For resources on creating great screenshots for the App Store, you may want to review the App Store Product Page information available on the Apple developer portal.
Please ensure you have made any screenshot modifications using Media Manager. You should confirm your app looks and behaves identically in all languages and on all supported devices. Learn how to use Media Manager to add custom screenshots for each display size and localization.
Since your iTunes Connect status is Metadata Rejected, we do NOT require a new binary. To revise the metadata, visit iTunes Connect to select your app and revise the desired metadata values. Once you’ve completed all changes, reply to this message in Resolution Center and we will continue the review.
NOTE: Please be sure to make any metadata changes to all app localizations by selecting each specific localization and making appropriate changes.