Final answer:
When Jeffrey high-fives Stephen, he might say something like "Good job, Stephen! That was an excellent presentation!" as a way to express praise and congratulations.
Step-by-step explanation:
When Jeffrey high-fives Stephen on his way out of the ceremony, he might say something like:
Good job, Stephen! That was an excellent presentation!
It's common for people to express praise or congratulations when giving a high-five, so Jeffrey's words would likely be positive and encouraging.