At this time, Shopify unfortunately doesn't allow third-party apps (such as Replay) to access the Files section of your shop. This would be any files/documents you've uploaded into your store using the Files Uploader located within your Store Settings.
If you've used this Files Uploader to add Images into your Theme, then when you use Replay to copy your Theme to your destination store, it will exclude these Images, since they aren't located and stored within the Theme itself.
These Images will need to be manually added to your destination store -- but never fear, it's actually a pretty simple task! :)
How to Manually Copy Theme Images to Your Destination Store
Note: We recommend creating a new folder on your Desktop and having it ready before you begin, where you can save these Images. The simplest we can make this, the better!
1. Start in your master store's Admin. At the bottom left-hand corner of the page, click on Settings.
2. From your Store Settings, select Files.
3. Click on the name/link for each uploaded Image to enlarge it.
One-by-one, right click on the Image and select "Save Image As...".
***When saving the Images, do NOT alter the Image/file name in any way. This is how your Theme in the destination store will know how and where to sort these Images automatically.***
4. Once you've saved all of the Images located here, go into your destination store. Follow Steps 1 and 2 again to open up the Files section in your destination store.
5. In the upper right-hand corner, select "Upload files".
6. Go to the folder on your Desktop where you've saved all the Images from your master store. Select and upload them all.
7. Using Replay, copy your Theme(s) if you haven't already. This step can be taken before you manually copy your Theme Images, or after (it doesn't matter).
Once both the Theme and the Images both exist within the destination store, the Theme should then automatically sort whichever Images belong within it.