The first set of Ichikata is suwari, and it tells a story about variation in distance and initiative.
The second set of techniques in Ichikata are standing techniques - wrist grabs that tell a story about variation on wrist release #1.
The third set initially appears to be about variations on shihonage, but then all of a sudden the kata throws in two forms of iriminage, forcing you to re-think what this set is all about. Well, it turns out that this set is about release #2. It is just sorta hidden because in the first several techniques tori is doing the wrist grab instead of uke. This illustrates the point that the releases can be done with any sort of connection.
In the first four techniques, uke reaches in for a chest/lapel/shoulder push/grab, and tori fades back slightly out of reach (creating sort of an airy, void feel to the techniques), picks up the wrist, and does shihonage, hikikime, sukuinage, and tenkai kotegaeshi. The last two techniques are iriminage done from release#2 and release #4 conditions.