Time Traveler in 1928 Charlie Chaplin Movie Footage?

Filmmaker George Clarke from Belfast thinks he’s come across something quite interesting — a time traveler talking on a cell phone in 1928. Sounds a little crazy, right? The filmmaker shows the evidence in a YouTube video, taken from footage on a DVD of the premiere of Charlie Chaplin’s The Circus at Graumann’s Chinese Theatre in 1928, and it seems everyone is talking about it!
The YouTube clip has over 1.5 million views. In the video, it looks like a woman is walking along the street at the premiere, with her hand held up to her ear as if she’s talking into a phone. But of course, there were no mobile phones in 1928. While we also have no idea what’s going on, if it IS a phone, the question is — who is on the other end of the line?