As Adobe Firefly is added to Photoshop more of its key features designed to speed up workflow and make life a little easier are revealed, one is Generative Fill (see video above).
This basically enables you to remove areas of an image's background using a standard brush and then paint in, or render in, a new background using text prompts. Photoshop already has this kind of feature in Content Aware, but this is next level stuff.
You're able to not simply replace entire or areas of a background but also layer in and add in small details, from new characters to adjusting shadows and lighting. For many artists this could simply be used as a tool to set lighting in a scene and alter the mood of a painting, which is then completed by hand.
Other features coming to Photoshop that are enabled by Firefly include the 'expand' tool that enables you to turn a portrait or aspect of a painting or photo into a full landscape. At 35 seconds in the video above you can see how a lake is added to a scene, and extends it, simply by typing 'frozen lake with reflections' into the prompt box.