The word "泡泡" is formed by duplicating the character "泡", which itself is a pictophonetic character composed of the water radical "氵" on the left, indicating its semantic relation to liquids, and the component "包" on the right, which provides a phonetic clue. This reduplication creates a noun that specifically denotes multiple bubbles or the act of bubbling, focusing on the plural and iterative aspect of the concept.