This article explains how Auto and Manual Accept settings on the Otter tablet and POS affect order confirmation and the flow of new orders between the tablet and POS.
Auto / Manual Accept Guidelines

Auto – Auto: No confirmation, new order notifies tablet but is automatically sent to POS without confirmation on tablet or POS.
Auto – Manual: New order notifies tablet but is automatically sent to the POS without confirmation, but will require confirmation on the POS
Manual – Manual: New order notifies tablet and requires first confirmation, then order is sent to POS after confirmation where a second confirmation is required on the POS.
Manual – Auto: New order notifies tablet and requires confirmation, then order is sent to POS and does not require a second confirmation.
NOTE: Setting tablet to manual is the only way to adjust prep time before confirming with Otter.