What will this code YIELD

Can you figure out what the following code will yield on the screen.

using System.Collections.Generic; using System.Windows.Forms;   namespace YieldReturnSpike {     public partial class Form1 : Form     {         public Form1()         {             InitializeComponent();               uxPeopleGridUsingYield.DataSource =                           new People().GetPeopleIWorkWith();               uxPeopleGridNotUsingYield.DataSource =                           new List<Person>(new People().GetPeopleIWorkWith());         }     }       public class People     {         public IEnumerable<Person> GetPeopleIWorkWith()         {             yield return new Person("Mo Khan");             yield return new Person("Joel Briggs");             yield return new Person("Luu Duong");             yield return new Person("Matt Gardiner");         }     }       public class Person     {         private readonly string name;           public Person(string name)         {             this.name = name;         }           public string Name         {             get { return name; }         }     } }

Here are the puzzling results:

As you can see when the data source is set to a list with deferred execution the list is not bound to the data grid. I really don't understand why this happens. In order to figure this one out I will have to gain more insight into how the databinding works under the hood. I'll post my findings once I get some answers.