Please try to act out the dialogue below by yourself and try to answer the question below!

Situation: During the opening ceremony of a branch office.

Mr. Smith: Hello, Mr. Tony Thank you for coming. I'm glad you can come. I really appreciate it.

Mr. Tony: Thank you, Mr. Smith, congratulations on the opening of your new branch office.

Mr. Smith: Oh, thank you very much, Mr. Tony.

Mr. Tony: By the way, how many branches have you got now, Mr. Smith?

Mr Smith: Hmm..., four altogether. This is the fourth one.

Mr. Tony: The fourth? Well, you've done a great job.

Mr. Smith: Congratulation once again in every success in the future, Mr. Smith!

Mr. Smith: You too, Mr. Tony. Enjoy the party, please. Oh, would you excuse me for a moment, please?

Mr. Tony: Yes, of course.

Sumber: Model 2018 - Direktorat Pembinaan SMA - Kementerian Pendidikan dan Kehidupan

Why did Mr. Tony congratulate Mr. Smith?