What is High-Res Grid Photo Mode on the H20T?
In DJI Pilot, by dragging to select an area in wide camera view, an image will be taken using the wide-angle camera while the gimbal rotates to automatically capture a series of photos at 20 MP of the selected area using the zoom camera at the current zoom level.
All of the images captured will be stored in the same sub-folder on the SD card, generating an HTML file that can be opened in a web browser to view the overview image and the detailed close-up images.