A middle-aged woman with red-hair, a white shirt, and a silver beaded necklace is holding a yellow cellphone against her ear while talking.
The woman had a blue cellphone.
The woman can not be holding a yellow and a blue cell phone, she either has one or the other. Although there is the posbility of her having 2 cell phones.
The cellphone is either blue or yellow. A woman is not necessarily middle-aged.
The cell phone is either yellow or blue, it can't be both.