[yaeger]

Isn't this the same as with product placement in TV shows?

Sometimes you see the characters using a Mac complete with logo visible and sometimes the logo gets covered.

The reasons for this may also come from both ends. Either Apple can say "We did not authorize the use of our trademark" or they could just enjoy the free exposure on TV. On the other hand, the TV shows producers could say "What we would do with displaying the logo in that way would be advertising, therefore Apple would have to pay us to show their logo. Otherwise we just cover it up"