Ozouni is a traditional dish with mochi. Usually it uses dashi so it makes it savory soup. (Can add chicken etc) mochi is not sweet in this case.
Daifuku is sweets (basically mochi filled with sweets - red bean paste in this case)
However she put white miso in it so supposedly it has a bit of sweet taste instead of fully savory.
Closest thing you can think of to compare w western food is adding candies/chocolate to chicken soup
Additional:
Osechi is traditional fancy new year meal set
While daifuku is usually w mochi/rice flour, manjuu is from other flour like wheat or buckwheat
Miso is fermented bean paste. Most of you know what miso soup is.
Instead of the savory dashi that's usually from kelp or bonito, she uses miso instead. There's red and white miso, red being more savory.