Why is this humorous?

[unpakwon]

Please help me understand the following in red.

An Apple employee accidentally left the next version of an Apple iPhone in a bar. The people who found it sold to the technology web site Gizmodo... Gizmodo promptly took it apart, and shared all its nifty details with the world.
Jobs called a Gizmodo editor himself, saying "This is Steve. I really want my phone back." Over several exchanges, Jobs was firm but also kept a sense of humor, beginning one call with, "it's YOUR NEW BEST FAVORITE PERSON IN THE WORLD."

Is this saying "I'm the person you like best in the world"? And is it humorous because it's an ironic expression?

Thank you.

[JohnParis]

Irony is "the expression of one's meaning by using language that normally signifies the opposite, typically for humorous or emphatic effect."
So, I'd say YES to your question.

[Tdol]

I'd agree as it sounds like a veiled threat to me.

[unpakwon]

Many thanks for the help.