Decomposing the purely absorptive signal into individual contributions allows us to estimate the contributions of individual energy transfer processes in the moleculecavity hybrid system. Because we have two exciton states for the system, hybridizing with the photonic excitation results in three polariton states, which we denote as |+⟩ (upper polariton), |D⟩ (middle polariton), and |-⟩ (lower polariton) states. The detailed expressions of these three polaritons are provided Sec. I of the Supporting Information, where the middle polariton state has a relatively small contribution of the photonic excitation, hence is denoted as the "dark" state |D⟩. The molecular transition dipoles between |G⟩ and these polariton states are also provided in the Supporting Information, Sec. I.