The images were snapped by a resident who lives in Cupertino and shared with TheApplePost. According to the photographer, construction crews were working on the building late at night, perhaps suggesting Apple is aiming to have it completed soon.
The visitor's center, made from glass, appears to include the same wooden tables that are found in Apple Stores, plus an accessory wall at the back, which makes sense as it will serve as both an Apple Store and an area for visitor's to stop by when coming to the Apple Park campus.
A rooftop observation deck is built into the visitor's center, allowing people to get a view of the main building, and it has a cafe and an outdoor seating area, according to building plans.
It's not clear when Apple plans to officially open the visitor's center on the campus, but given that it looks nearly complete, it could perhaps open on Tuesday alongside the Steve Jobs Theater where Apple's iPhone event will be held.