The Tide Empire's group couldn't just leave right away since that would be too discourteous.
The only thing that they could do was wait for a bit before leaving.
At the same time, it wasn't as if they could just remain silent while waiting to leave, so they discussed a few simple matters with the Merman King.
Since the Tide Empire was close to the Merman Empire, there were some things that they had to discuss with each other in terms of the cooperation between them. There were some simple matters such as trade routes that had to be discussed, though it wasn't necessary for the rulers to discuss it in person like this.
Most of these matters would usually be discussed in letters sent between the two empires.