Mavericks OS X Server Software Updates: "Duplicate" entries? How do they differ?
They're different versions of the software (Safari v6.1.4 in this case) that the client computer will choose between based on... well, something. The info about what the differences are (and which is needed for which clients) is all in computer-readable format, not really human-readable.

You can download the two packages, then search under /Library/Software Update/Data/html/content/downloads for them. And I do mean search -- the 031-02224 is in .../downloads/17/37/031-02224/8gxq9vhxcra3e5adif9fhvafxoefypqvlx. Spotlight will find the folders by the package ID, but only if you search in the relevant parent folder (if you do a general search, it omits them because they're considered "system files", not the sorts of things normal users would be interested in).

Once you've found the relevant folder read through the various files (especially the .pkm and .dist files), you'll find that 031-02224 is the version for Lion, and 031-02225 is the version for Mountain Lion.

So... it's possible to find out, but not easy (and far from user-friendly).