New Tab page Wallpapers - Select custom one

Hi Mozilla Firefox team, I saw that you added the option to select wallpapers for the New tab page, I really like that and I've been waiting for this feature for so long, but there are only a plethora of pre-selected wallpapers that you can choose from. Why not add the option for the user to upload and use there own image as a wallpaper? Or even option for the users to upload their wallpapers similar to how the "Themes" work. Thanks for taking me into consideration! Vladi