Object-substitution masking (OSM) refers to when the delayed disappearance of a sparse mask that spatially surrounds but does not overlap the target impairs target perception. Two major theoretical accounts have been offered to explain OSM: the object-substitution account, which stipulates that masking occurs when a separate mask representation replaces the target, and the object-updating account, which espouses that masking is the product of a single representation initially containing information about the target that is modified to reflect the mask. Here I critically review the evidence that has accumulated over two decades for the two models, and find the evidence overwhelmingly in favor of the object-updating account. This object-updating account places OSM in the larger framework of related phenomena such as a repetition blindness, apparent motion, and object correspondence through occlusion that gauge how the visual system assigns episodic object representations in the face of dynamic and ambiguous input. Implications for visual cognition more broadly are discussed.