Is it possible to control the camera via touchscreen during an Intelligent Waypoint flight?

Hopefully the title is self explanatory, but if not, what I'm looking to do is this:

After programming a flight plan to be executed automatically via GPS, I'd like to be able to control the gimbal camera based on holding and dragging my finger on the screen rather than using the rocker. I find it smoother, but it doesn't appear to work for me when I try it. Am I missing something?