Dear Sam,
Thank you for going above and beyond to make our new hires feel welcome. When you heard one of the new hires manager was going to be out of office for personal reasons on their first day, you took it upon yourself to sit with them for the first hour of their day and arranged for another manager to step in. You also printed out the cutest sign for their desk to make sure they felt welcome!
Keep up the great work!
Johnathan