Recently released footage from the 1928 premiere of Charlie Chaplin's "The Circus" appears to show a woman holding and speaking into a cellphone. While some believe the woman to be an "alien," this is the more likely scenario!
Is it possible that what we are actually looking at in the linked photos are "Time Travel Tourists"? Let's entertain the idea that time travel is possible. If you wanted to go back, observe 1920’s culture and not impact the time line this is how you’d do it, with a costume and a small communication device, suggesting that the individual may be communicating with other time tourists who ventured off as a small group. Of course, we are thinking here that one could not communicate through time so the device must have been used by the tourists to communicate with each other.
It reminds me of the recent modern-era hipster captured in a photo taken in 1941, which apparently is authentic, fostering hope that the time travel theory is real because it suggests human technology advancing for at least another century (or beyone) and perhaps that we had learned enough to not go back in order to change things or profit from manipulating history, altering the timeline. That would be true advancement!