Feeling Ways About Things
Jesus christ.
First, there would be no cell towers, rendering the phone useless except for playing MP3s or Angry Birds.
Second, even if they managed to send a whole cellphone network back in time, they probably also have better bluetooth headset technology than we do right now, meaning you wouldn’t even see the goddamned earpiece because the first lesson of time traveling is to not let the fucking natives know you’re from the motherfucking future.
Third, that was a pretty old person using a small “cell phone.” Have you ever watched an old person try to use a cell phone? I rest my case, your honor.