Question

Why this displays data:

 <ItemsControl ItemsSource="{Binding Path=.}">
                <ItemsControl.ItemTemplate>
                    <DataTemplate>
                        <StackPanel Orientation="Vertical">
                            <TextBlock FontWeight="Bold" Text="{Binding Category}" />
                            <TextBlock Text=", " />
                            <TextBlock Text="{Binding Title}" />
                            <TextBlock Text=" " />
                            <Label Content="{Binding ImageUrl}" Foreground="Blue" />
                        </StackPanel>
                    </DataTemplate>
                </ItemsControl.ItemTemplate>
            </ItemsControl>

and the following displays empty rows (but as many as there dataitems):

 <ListBox ItemsSource="{Binding Path=.}">
                <ListBox.ItemTemplate>
                    <DataTemplate>
                        <StackPanel Orientation="Vertical">
                            <TextBlock FontWeight="Bold" Text="{Binding Category}" />
                            <TextBlock Text=", " />
                            <TextBlock Text="{Binding Title}" />
                            <TextBlock Text=" " />
                            <Label Content="{Binding ImageUrl}" Foreground="Blue" />
                        </StackPanel>
                    </DataTemplate>
                </ListBox.ItemTemplate>
            </ListBox>

Answer 1

1. Try putting a breakpoint in your getter for Category. Does it get hit?
2. Look at the Output window in VS, do you see any Binding errors?

I created a test app in Blend, with the following code, and I see the list in both cases. So maybe there is some problem in your other code (Binding, Code-behind, Viewmodel, etc), but both your ListBox and ItemsControl should work if wired up correctly.

<Grid x:Name="LayoutRoot" DataContext="{Binding Source={StaticResource SampleDataSource}, Path=Collection}">
    <Grid.RowDefinitions>
        <RowDefinition></RowDefinition>
        <RowDefinition></RowDefinition>
    </Grid.RowDefinitions>

    <ItemsControl Grid.Row="0" ItemsSource="{Binding Path=.}">
            <ItemsControl.ItemTemplate>
                <DataTemplate>
                    <StackPanel Orientation="Vertical">
                        <TextBlock FontWeight="Bold" Text="{Binding Category}" />
                        <TextBlock Text=", " />
                        <TextBlock Text="{Binding Title}" />
                        <TextBlock Text=" " />
                        <Label Content="{Binding ImageUrl}" Foreground="Blue" />
                    </StackPanel>
                </DataTemplate>
            </ItemsControl.ItemTemplate>
        </ItemsControl>

        <ListBox Grid.Row="1" ItemsSource="{Binding Path=.}">
            <ListBox.ItemTemplate>
                <DataTemplate>
                    <StackPanel Orientation="Vertical">
                        <TextBlock FontWeight="Bold" Text="{Binding Category}" />
                        <TextBlock Text=", " />
                        <TextBlock Text="{Binding Title}" />
                        <TextBlock Text=" " />
                        <Label Content="{Binding ImageUrl}" Foreground="Blue" />
                    </StackPanel>
                </DataTemplate>
            </ListBox.ItemTemplate>
        </ListBox>
</Grid>