Here's The Statement From Their Discord:
Hey everyone we're testing a new feature today called "Pan"
How does Panning work?
Underneath your upscales you'll see arrow buttons ◀️ ▶️ 🔽 🔼
If you click an arrow it will extend your image in that direction
If you type /settings and click Remix mode you'll have the option to change your prompt as you extend your image. Use this to tell panoramic stories!
As you pan out your image we will keep extending it even though the resolution will become very large
Yes, that means you can keep panning multiple times!