As it's a bit of a separate issue, I figured it may be better to deal with it in a separate thread, however.
…meaning it isn't real size.
Also, "real size", "actual size" and "100% zoom", all mean the exact same thing.
To have "real size" display the print size, is deeply confusing and misleading. It should instead be called "print size", to more properly reflect what it actually is
…and how is print size determined, anyway, if it isn't based on pixels?
Granted, for photos where the dpi (or dpi equivalent) of the camera is included in the metadata, or maybe in images where the same is done (based on the dpi of the monitor of the person who created it? I suppose that could make some sense?) …but most images don't have any such thing.