  Localized bulk excitations in AdS/CFT are produced by operators which modify
the pattern of entanglement in the boundary state. We show that simple
models--consisting of entanglement swapping operators acting on a qubit system
or a free field theory--capture qualitative features of gravitational
backreaction and reproduce predictions of the Ryu-Takayanagi formula. These
entanglement swapping operators naturally admit multiple representations
associated with different degrees of freedom, thereby reproducing the code
subspace structure emphasized by Almheiri, Dong, and Harlow. We also show that
the boundary Reeh-Schlieder theorem implies that equivalence of certain
operators on a code subspace necessarily breaks down when non-perturbative
effects are taken into account (as is expected based on bulk arguments).
