Missing Bundle use to donate the Junimos through the golden scrolls which can be found in the Community Center. If the bundles will be full then, Junimos will provide you with a reward.
If all of the bundles will be full in the Community Center’s specific room then, Junimos will reward you and grant permission that has a positive point for the whole group.
The reward for Missing Bundle will be provided immediately. However, you will get rewards after completing all the bundles in the room. If you will also be provided by oif at the end of the day with a cutscene depicting the Junimos as the reward.
You must have to remember that if you will not collect the individual bundles before completing the room. You can find the rewards in a small bag of brown color on the left of the Junior Hut further then the golden scroll disappears. This bag will persists after the completion ceremony of the Community Center, till all of the objects are retrieved.
Only a few of the Missing bundles will be shown in the object and they have slots to fill (for example, Artisan Bundle: 12 objects and 6 slots to fill). For this situation, you can choose any of the objects which you would like to use for filling the bundle. You will not need to use all the shown objects, use sufficient to fill the slots.