What is mood?
Mood is an object that contains a single color or a sequence of time and color/color temperature/special action (on/off).
With this sequence you can define active moods that changes according the specified time. If time is 0 actually the command is send every 100us for single bulb and 1s for a group (requirements by Philips). Whit the moods you can define a lot of custom color changes. In some of the feature releases will add also an effects between color changes.
Mood itself is not related to any bulb/group. Here comes the presets. So mood is pretty much the action that will be executed for group/bulb in the preset.
You can also execute the mood directly for bulb/group if needed.
You can define as many moods as you want and you can assign individual icon for each one. So far the list of icons is not so long, but it will be updated.
If color mood is created even you select an icon the color will be displayed instead of icon.