Cup on a table, heat or work process?

[Kites]

Homework Statement

A cup sitting on the table contains 200g of water. You measure it at a certain time and it is 20 degrees Celsius. You leave the room and come back 10 minutes later. It is now 25 degrees Celsius. What can you conclude about the heat added to the water? [hint trick question]

Homework Equations

The Attempt at a Solution

My attempt is that I believe this is still heat transfer between a warmer environment and a colder cup. The fact that it says a trick question makes me wonder. Is this actually work being done?

 

[Delphi51]

I don't see a trick!