How do I change the icon/preview of a sprite within the editor?

This seems like a simple thing to do, but I can't figure it out. When I create a sprite and upload the spritesheet, the full spritesheet is what gets shown in the editor/menus rather than the proper frame. This makes is very difficult to place the sprite where I want it. This does not happen consistently, and I don't know why. Is there a way to make the editor display the proper frame/animation of the sprite?

I'm guessing it's not intended for you to have a copy of the spritesheet in there like that? Either way, that worked. As I thought, a simple solution that I just failed to see.

For anyone in the future: The icons in the editor don't change until you reload Construct.

Thank you!