Neznam za te ikone, ja imam p990, ali koliko sam ja upucen moguce je promjeniti te ikone na m600...

Ovo ti je sa sluzbenih stranica od Sonyericssona:
Customize the UI
It is possible to customize the icons and the shortcuts in standby mode. Mark the icon you want to change, choose more and then replace. Brows to the application etc. you want to replace the prievious one with.
Link