The buttons looks similar and I had a hard time determining which one was which. Maybe one need to be bigger than the other or have them different colors.
Yes, the size or shape of the buttons could be different. The raised volume and circle (or is it power?) icons on the buttons are too small to tell them apart by feel and even difficult visually if you wear glasses or are in poor lighting.
This is really good feedback - I will relay (no pun intended) this to the team and see if a solution to this is in the works for future iterations.