My guess is that it’s earplugs. Even Shrillary cant stand to hear herself speak.
I know the contours of that piece. It is, for one thing, hard and shiny i.e. not an ear plug. Its contours are the shape of an earpiece, either a hearing aid or a Wi-Fi receiver.
Well that is interesting. Remember the seizure episode when journalists were gathered around her? Well, noises and confusion can trigger seizures and it might be an ear plug to help prevent sound disturbances in that ear.