If you work with batches consisting of multiple one-page documents, you may want these documents to take up all the screen space, so that you can see as many documents as possible at once. On the other hand, if you work with multi-page documents, to you may want to start each document on a new line to separate them visually
1. Enable "Thumbnails" or "Alt+2" in the current view batch.
2. Documents use up all the screen space
3. For Each new document starts a new line, enable View > Thumbnail options > New Documents Starts New Line
https://www.abbyy.com/flexicapture-downloads/distributed-invoices/ - Release notes for FlexiCapture 12 Release 3 Update 1