For one it needs text to explain it, which makes the text superior to the icon. That could be ok, an icon can be as a support, but the text is so small you can barely read it. That could be ok, if you could start reading it before it becomes relevant or if you can take your time to read it. In this case the icon acts superior, but can be very confusing. For example there are two ‘end call’ buttons, but one ends the current call while the other ends the incoming call, you need the visually inferior element to understand the difference. Second is the meaning the big red button, which changes function once you got an incoming call (it no longer means end current call, but now means reject incoming call). You need to guess by the context what the current function is.