Sales people say the darndest things.
CS5.5 files can be opened in CS6. CS6 files must be saved as IDML to open in CS5.5. I has been this way since the dawn of InDesign: new versions can open old files, but not the other way (though the newest releases of CC versions can use a cloud-based IDML converter to eliminate the manual step).
In you second screen shot, the linked images are missing, hence no previews. I don't know why the two text frames on the pasteboard have changed from single-column to two-column, and it looks like the same thing has happened to the Employee of the Month headline. It's not unusual for text to have different spacing between versions which can affect line endings.