Looks as if there are three choices: "Digital Download of PC or Mac, disc with Frustration-Free Packaging, and disc with Standard Packaging" with this explanation at the bottom, "Frustration Free Packaging is the same product you might find on a store shelf - just in better packaging."
The answer was stated above. "Frustration Free Packaging puts the disc in an easy to open and environmentally friendly CD-sized sleeve instead of the big, 95% empty, display box you'd get at a retail store." Standard Packaging is the think hard to cut plastic. Frustration Free is the easier to open packaging. Frustration free has nothing to do with download versions.