A few pieces of context - this builds on the insight that underlies WiTricity - https://witricity.com - near-field coupling of designed resonators for non-radiative power transfer. Specifically, this can enable very high efficiency wireless transfer in the near-field of resonators, which at these wavelengths is on the order of 1-5 meters. This is qualitatively different from other approaches to wireless power transfer and does have some real scientific insight which originates from the electromagnetics/ photonic community.
More specifically, this specific results builds on an insight from the same research group which led to a Nature paper in 2017: https://www.nature.com/articles/nature22404/ - that using an non-linear saturable gain element in a parity-time symmetric configuration enables robust power transfer in a range of conditions such as moving and the presences of obstacles. There's interesting underlying science here that shouldn't be missed for the focus on the application.