Guardian is no stranger to reactions such as these. They hail from a continent riddled with war. So they don't acknowledge the other's skittishness, and instead simply stay in place and tilt their head slightly as Mettaton reaches inside the box.

"A companion sprite?" they offer. They can't really see from where they stand, but they can guess. Their own floats forward, chirping cheerfully at Mettaton and the bot in his hand. "Lucky find! Don't see too many of those lying around."