For packaging purposes, it is important to understand how snapshot files are located, as the mechanism for doing is it quite different from the mechanism for determining the location of ICs. If a snapshot is not present in the SnapshotCache, then packager attempts to locate the snapshot file in the following locations:
The EpImageSnapshot class method retrieveSnapshotFromFile:ifAbsent: contains the code for performing the look up, so you might find it easier to remember this method and look at the code within it if you need to recall the directories that are searched for .snp files.