Issue
After setting up AEM 6.4 SP1 with runmode dynamicmedia_scene7, and then looking in TouchUI at Tools - Assets - Viewer Presets, the list of ViewerPresets is empty, whereas it would be expected to contain all the OOTB Viewer Presets
Environment
AEM 6.4 + SP1 running with runmode=dynamicmedia_scene7
Cause
Prerequisite for the OOTB ViewerPresets to appear is the configuration of the DMS7 CloudConfiguration.
Resolution
If you did not setup the DynamicMedia CloudConfiguration, do so now and the ViewerPresets will appear.
If you created the DynamicMedia cloud configuration earlier, and still cannot see the ViewerPresets, in the TouchUI go to Tools - Cloud Services - Dynamic Media Configuration, Edit and Save the configuration, and that should regenerate the Viewer Presets.