  While polarons --- charges bound to a lattice deformation induced by
electron-phonon coupling --- are primary photoexcitations at room temperature
in bulk metal-halide hybrid organic-inorganic perovskites (HOIP), excitons ---
Coulomb-bound el\-ectron-hole pairs --- are the stable quasi-particles in their
two-dimensional (2D) analogues. Here we address the fundamental question: are
polaronic effects consequential for excitons in 2D-HIOPs? Based on our recent
work, we argue that polaronic effects are manifested intrinsically in the
exciton spectral structure, which is comprised of multiple non-degenerate
resonances with constant inter-peak energy spacing. We highlight our own
measurements of population and dephasing dynamics that point to the apparently
deterministic role of polaronic effects in excitonic properties. We contend
that an interplay of long-range and short-range exciton-lattice couplings give
rise to exciton polarons, a character that fundamentally establishes their
effective mass and radius, and consequently, their quantum dynamics. Finally,
we highlight opportunities for the community to develop the rigorous
description of exciton polarons in 2D-HIOPs to advance their fundamental
understanding as model systems for condensed-phase materials in which
lattice-mediated correlations are fundamental to their physical properties.
