It doesn’t do anything: from the horses mouth:
Lexus Customer Relations
Dear Dave,
Thank you for your response. I recognise that the inclusion of an e-Store component may seem counter-intuitive, as it is currently inaccessible.
The Lexus Premium Navigation system was built with future enhancement in mind. By shipping the system with an e-Store component, we leave the door open to add additional functionality at a later stage, rather than require customers to visit a Lexus Centre for system enhancements. Nevertheless, I o the perception this could create and I'm sincerely sorry for any disappointment caused.
We have, at the time of writing, no clear plans or timelines to enable this feature, though I cannot say if this will change at some point in the future.
I hope this offers some context, and thank you for taking the time to bring this to our attention.