High-S/N quiescent galaxy (Plate-MJD-Fiber 394-51913-561): principal component analysis (PCA) and VAE reconstructions of the Na 5896 absorption line (left) and N II 6550/6585 and Hα emission lines (right). The noise band represents the SDSS stated pixel uncertainties. The median S/N of the spectrum is 78 in the left panel and 102 in the right panel. Both reconstructions find the significant Na absorption and N II emission with only two components, but the VAE provides a better reconstruction overall than PCA with the same number of components.