This is purely ornamental, and looks cool. Someone decided it would be cool to mod the apple logo into its own monitor. Be the coolest guy in the cafe, you know.
It reminds me of back when I worked at Microsoft. There was a big initiative among the mobile computing teams -- getting these mini monitors working so that you could check your next appointment / read your email without ever opening your laptop.
That's because standby mode sucked so much on Windows (kind of still sucks today, compared to OS X) -- rather than fix standby, it was decided that lets make ANOTHER device that you could tell OEMs to make and built into the outside of the laptop so people don't even have to open their laptops anymore.
This approach reminds me of the millions spent on designing a pen that would work in space by NASA. What did the Russians do? Use a pencil.
What did Apple do? Make standby mode actually work.