Business Manager Team allows users to use their custom logos (the one displayed in the top left corner). When creating custom logo, please take a note of the default background color (#008080) - it is recommended to create background layer when working in an image editor.
You can also open installation folder on your server and navigate to wwwroot\images\general\logo.svg to check how default logo looks like.
Custom logos should be placed to the wwwroot folder (not to the Images folder), and name of a file should be logo_custom.svg or logo_custom.png. After placing custom logo to the specified folder, it may probably be required to restart application pool in the IIS.