What App Objects Are Included/Excluded By Export/Import App?

Below are app objects included/excluded when export/import app:

1.  For an unpublished app, all content is exported.
2.  For a published app, only published and approved content that is part of the .qvf file is included in the export. 
3.  Extensions are not included in the export. The extensions can be obtained from the shared folder given during the installation, for example: \\<domain>\QlikShare\StaticContent\Extensions.
4.  When importing an app to a server, or exporting an app from a server, related content that is not stored in the .qvf file, such as images, is also moved. The related content is stored in a separate folder: %ProgramData%\Qlik\Sense\Repository\AppContent\<App ID>. Each app has its own app content folder, with the app ID as the folder name.
5.  Data connections are not included. If the app contains ODBC data connections, you must create new connections, or use the ones that already exist at the new site.

Note,

1.When you export an app, you can optionally export the app without any data. When importing an app without data, you can replace apps with sheets and stories without impacting the data or data model.
2.The app file size displayed in the QMC differs from the file size on disk. This is because the size in the QMC only includes data objects, such as fields, tables, and document properties, and not visualizations, bookmarks, measures, etc, that are also included in the .qvf file.

Reference links:

https://help.qlik.com/en-US/sense/November2018/Subsystems/ManagementConsole/Content/Sense_QMC/export-apps.htm
https://help.qlik.com/en-US/sense/November2018/Subsystems/ManagementConsole/Content/Sense_QMC/import-apps.htm