What constitutes a flight review for the purposes of eligibility for a remote pilot certificate under 14 CFR 107.61(d)(2)?
You have to take into account the intent of the regulation.  I think the regulations intent is to ensure the pilot has been evaluated on his knowledge within the previous two years by either a CFI or examiner.

With that in mind, a flight review by a CFI or passing a practical test by an examiner satisfies the requirement for the remote operator to take the full initial knowledge test.



From the preamble to the Part 107 final rule.


  The FAA proposed that a certificated remote pilot must also pass a recurrent aeronautical knowledge test every 24 months. Like the flight review requirement specified in §61.56, the recurrent knowledge test provides the opportunity for a remote pilot’s aeronautical knowledge to be reevaluated on a periodic basis. The FAA adopts this provision as proposed, with one change. As discussed in III.F.2.i, the FAA exempts part 61 pilot certificate holders from the requirement to complete recurrent knowledge tests as long as they satisfy the flight review requirements of §61.56 and complete an online training course every 24 months


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  The FAA agrees with commenters who suggested that requiring part-61- certificated pilots who satisfy the flight- review requirements of §61.56 to take an initial or recurrent knowledge test is unduly burdensome. Through initial certification and subsequent flight reviews, a part-61-certificated airman is required to demonstrate knowledge of many of the topic areas tested on the UAS knowledge test. These areas include: Airspace classification and operating requirements, aviation weather sources, radio communication procedures, physiological effects of drugs and alcohol, aeronautical decision-making and judgment, and airport operations. Because a part 61 pilot certificate holder is evaluated on these areas of knowledge in the course of the part 61 certification and flight review process, reevaluating these areas of knowledge on the initial and recurrent knowledge tests conducted under part 107 would be needlessly duplicative. 


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