The Cover step is your thumbnail. Four ways to make one: Pick a frame straight from the clip, Frame + AI to restyle a frame, Generate a fresh image from a prompt, or Upload your own. Choose Textless for a clean image, or With text to have AI render a headline right onto it, and set the tone from conservative to creative. Every image you make is saved to a gallery for this clip, so you can compare and reuse. Covers are a ProAI feature and use a few AI credits each.