Tip: You can customize your wallpaper by on your Mac, choose View in the menu bar, then choose the room to which the accessory is assigned.
Double-click the accessory, click Settings, then click Include in Favorites.
Click Done, then click the Home tab.
The accessory appears as a favorite.
You can change the icon of a lightbulb; you can’t change the icon of other accessories.
In the Home app Use scenes to control multiple Home accessories on MacApple Support article: Get notifications for your HomeKit accessories