BinaryRibbonControlContextualTabSet

Put the tabs in TabItems, give the set a TitleText such as "Picture Tools" and a BackgroundColor, and keep it ready, for example as a resource. When the user selects the kind of thing the tabs act on, assign the set to BinaryRibbonBarPanel.ContextualTabSet; when they move away, set that back to null. The ribbon shows one set at a time.

The tabs work like any other: they are selected, carry key tips and give way to the window's width in the same way. Adding a set to BinaryRibbonBarPanel.ContextualTabSets connects it to the ribbon without showing it.

A Picture Tools set kept as a window resource and shown while a picture is selected.

<bm:BinaryRibbonWindow.Resources>
    <bm:BinaryRibbonControlContextualTabSet x:Key="PictureTools" TitleText="Picture Tools" BackgroundColor="#FFE8A33D">
        <bm:BinaryRibbonTabItem HeaderText="Format">
            <bm:BinaryRibbonGroup TitleText="Size">
                <bm:BinaryRibbonButton Content="Crop" LargeImage="Images/Crop32.png" Click="OnCrop" />
            </bm:BinaryRibbonGroup>
        </bm:BinaryRibbonTabItem>
    </bm:BinaryRibbonControlContextualTabSet>
</bm:BinaryRibbonWindow.Resources>

private void OnSelectionChanged(object sender, RoutedEventArgs e)
{
    ribbon.ContextualTabSet = editor.SelectedObject is InvoiceLogo
        ? (BinaryRibbonControlContextualTabSet)FindResource("PictureTools")
        : null;
}