If you’re preparing for a commercial certificate and meeting the solo requirements of 61.129 using the Duties of Pilot in Command with Authorized Instructor then pay attention to how it’s logged.
Kuhn (2014): If choosing the option with an authorized instructor on board, the pilot (Commercial pilot trainee) can log the time as PIC, provided she/he is rated in the category and class of aircraft already (i.e. has a Private Pilot certificate with such a rating). She/he does not log it as dual instruction received, because it is not considered instruction (as it stands in lieu of solo). The logbook should clearly show that the flight was performed specifically to satisfy 61.129(a)(4). The CFI can log it simultaneously as PIC according to 14 CFR 61.53(e)(3), because she/he is acting as an authorized instructor on board.