Default Is HEADPHONES OUTPUT POWER decides quality of ouput music?

This graph I took from phonearena. Z2 has low HEADPHONES OUTPUT POWER. (Lower than Lumia 520 and some Xperias).

Is it effect to sound quality or just the sound volume ?

Attached Thumbnails
Click image for larger version

Name:	Capture.JPG
Views:	87
Size:	43.3 KB
ID:	2740548