Input/output impedance when disabling the ADA4622-1

I'm curious about the shutdown/disable feature of the ADA4622-1.

What is the impedance looking into the ADA4622-1 at its inputs and output when the part is in shutdown?  I like the idea of a circuit like Figure 99 of the datasheet, but what extra load is being added?  Gigaohm to V+ or V-?

Thanks,

Eric