Spoiler warning obviously if you haven't seen Season 2 Episode 14 "Escape from Earth-2." Also spoilers for The Man in the Iron Mask (1998) if you haven't seen it. I'll give you a chance to run now and save yourself!
Still with me? Cool. This is a continuation of my fan theory about the identity of Zoom being Earth-2's Henry Allen and who I think the Man in the Iron Mask is. If you haven't read it yet here's the link so you can catch up.
In Escape from Earth-2 we are introduced to a mystery man in a metal mask who Zoom is keeping prisoner. I've seen various theories to his identity; most of them thinking our Man in the Iron Mask is the real Jay Garrick or Jay Garrick's twin etc. I'm guessing most of these theories stem from the fact that the MitIM used the POW tap code to say "Jay." Personally I think this is too obvious for The Flash writers and very unlikely since we've see Garrick and his Earth-1 version.
For my theory I'm going to give a little background on the symbolism of the Iron Mask.
For those of you who haven't seen the 1998 movie starring Leonardo DiCaprio, the plot revolves around an evil selfish king who keeps his good and kind identical twin brother locked up in a jail cell and forces him to wear an iron mask to hide his identity. Eventually the good twin is broken out from jail by the three original Musketeers (Arimis, Athos, and Porthos) and they attempt to switch the twins so they will have a kind king instead of the cruel one they currently have.
The Flash's version is clearly a homage to the tale given the style of the mask. I, however, don't think our MitIM is any version of Jay Garrick. I believe he is Earth-1's Henry Allen kidnapped by Zoom.
My reasoning goes like this: in the movie MitIM the evil twin (Earth-2 Henry Allen) puts his good twin (Earth-1 Henry Allen) in a mask to conceal his identity. I think Zoom is a smart villain and has been systematically sending Earth-2 counterparts of people Barry cares about to trip him up. So to me it would make a lot of sense if Zoom came through a breach, kidnapped Earth-1 Henry Allen, and has been pretending to be him whenever Barry needs him. It would explain why a man who didn't get to raise his own son due to being in jail would spend all of his free time away from his son(something that has never made sense to me until this theory). The show runners love to tarnish Barry's loved ones (Linda, Catelyn, Cisco, and Earth-2 Joseph) and so far the only person that hasn't been ruined for Barry is his own father.
My last piece of evidence are the MitIM's hands. If you look at them they're weathered like that of an older man. I spent a good hour on Google images looking at Henry Allen's and Jay Garrick's hands and I can say with confidence that those are John Wesley Shipp's hands. In the above two pictures you can compare the tanned age marks on the back of Henry's and the MitIM's hands. They match up pretty perfectly.
Now for why the MitIM was tapping Jay's name, I'm not sure. My guess would be a warning about either restoring Jay's speed, which could be stolen again by Zoom, or he was trying to warn them of Jay's alleged upcoming death at Zoom's hands.
Overall I'm pretty confident that Zoom is Earth-2 Henry Allen while the Man in the Iron Mask is Earth-1 Henry Allen.
What do you guys think?