That is because if time travel is ever perfected it might be fun to do something like that just to mind fuck the future generations. It could be a guy in drag playing a joke on us. If I invented a time travel machine I would want to meet William Shatner and take him back in time to be an extra on Star Trek. That would really blow the Star Trek geek's minds.
If it weren't for our time period and the prevalence of cell phones it wouldn't stick out as anything other than a crazy old lady talking to her hat.
Well, it's one of the extra features on that disc. It's the opener at Grauman's Chinese Theater, so I can't imagine that film has been watched extensively, and certainly not on a big screen tv or in HD.
Since my time doesn't equal your time (speed and gravity can slow time) if I traveled very fast... I could speed away from Earth and return in what would appear to me as in the future of earth... in which case I would have what would appear on earth as very old technology... not new.
If I traveled to an era that didn't have portable phones, I so wouldn't use one in front of a ton of people in one of America's most populated cities. It's a cool video though. I have no clue what that person is doing.
It is a pretty funny example of looking at something in the past and then trying to explain it from our current perspective... and what is crazy is that if we saw that lady today... we wouldn't even have considered that no it isn't a cell phone in her hand... and our assumptions today would be very incorrect. We gloss over so much information in RL. I came home from beach a few weeks ago... see the paint cans I put in front of the cat door in the garage pushed in... think to myself... damn Racoon coming in garage looking for food again... then go to unlock door into house... but it pushes open... I think... damn I didn't push it all the way shut... then my son says... 'it smells funny in here'... then I noticed items on my computer desk shuffled around... I think damn cats... and it isn't until my wife asked where all her jewelry went that I realized someone broke into the house. I'd make a crappy private detective that is for sure.
I think we just naturally assume that our house is our castle... our safe zone.... and it isn't until that bubble is broken that we come back to reality.
The first thing I would do if I teleported back to 1928 would be to walk around in public yapping on a phone-like device. This would make me not stand out at all.