Its actually probably not, but at the same time its probably going to very customizable, both in the font, but also the background image. Put a blue tint on it and its very much like an old school Final Fantasy window prompt. Also as others have said this is the image style that the current UI director is known to use all the time, from Vagrant story to Final Fantasy Tactics, to the screen above in Ogre Battle.
Furthermore my FFXI chat window used to look very similar to that box with some of the various changes you could make to it. The main difference is the centerized boxed approach that FFXIV has deployed except now its not transparent anymore.
