Bigger, so it would float
The first Mango was 12 cm across, and the sums said it would sink. So the whole body grew by a fifth. Volume grows faster than weight when you do that, and now Mango floats with about a quarter of it above the surface.
The extra room went straight to the sound: about 800 cm³ inside instead of 460, shared between the battery and the bass. It still fits in one hand.