When selecting properties to export or include in columns, you have an endless list of properties. In most cases, there are a bunch of empty properties that are almost never used. It would be incredibly helpful when picking these properties to have a short preview of the values you might find in it. If there are very few, or add little to no info, it could also say “99% of contacts have this empty”.
This would make it a lot faster to set up reports, lists, columns for exporting and so on.