Kilonovae are the optical-NIR transient of rapidly expanding, radioactively decaying fireball of heavy elements ejected from the merger of neutron stars. The geometry of kilonovae is a key diagnostic of the physics of merging neutron stars (and the collapse to a black hole) with current hydrodynamical merger models typically showing aspherical ejecta. Previously, Sr II and Y II were identified in the spectrum of the first well-studied kilonova AT2017gfo, associated with the gravitational wave event GW170817. In this talk, we show that combining the strong P Cygni absorption-emission spectral feature and the blackbody nature of the kilonova spectrum, to determine that the kilonova is highly spherical at early epochs. Furthermore, using a unified temporal series of optical/near-infrared spectra from 0.5 to 9.4 days - combining observatories from across the globe - I will show how the observed radiative field is also nearly spherically symmetric. The near-spherical geometry and blackbody nature suggest early spectra of kilonovae may provide excellent precision cosmic distance measurements using the Expanding Photosphere Method.