Leica RAW Files - Viewer - high-quality rendition?

Hi all, I have RAW files here from a Leica M 240 that I imported into C1. When I edit these RAW files, for example, the resolution in the Viewer is different . When I go into the photo it gets better. If I zoom out the photo completely, the quality decreases significantly. What is the reason for this?

NOT FOR ME: The Viewer delivers a high-quality rendition of your selected image(s)