I noticed after the release was implemented in preview that the banner image is now rounded. As a result, there is white space around our image and space around the white space 'so to speak'. I have attached an example with our image blurred for reference. I see in the What's New Viewer some UI updates this release but didn't find anything specific to the banner. Maybe I overlooked this info. Can SAP confirm if this is intentional? I don't see that the image dimensions changed. If I try to upload/edit a new version of the photo to fill the space it doesn't work.
The larger banner image and rounded corners is expected however the large empty space when the banner image is disabled is being investigated as a defect. Communication will be centralized via kba 3392769 - [2H 2023] - Banner image on the Home Page is showing larger after release - SAP for Me
You may want to watch the KBA