I don't understand why they don't show the Windows UI on https://www.sourcetreeapp.com/ https://www.sourcetreeapp.com/ if they already know I'm using Windows by

I don't understand why they don't show the Windows UI on https://www.sourcetreeapp.com/ https://www.sourcetreeapp.com/ if they already know I'm using Windows by showing me the "Download for Windows" button.