The observed items are conditionally independent of each other given an individual score on the latent variable(s).
This means that the latent variable(s) in a model fully explain why the observed items are related to one another.
If the analysis is extended to also look at the education level of these people, the following tables are found.
Thus if a separation is made between people with high and low education backgrounds, there is no dependence between readership of the two journals.
If educational level is never actually observed or known, it may still appear as a latent variable in the model.