ImageBrush repeat image, VisualBrush video
<Rectangle Margin="135,102,166.5,110" Stroke="Black">
<Rectangle.Fill>
<ImageBrush ImageSource="/Assets/wallhaven0.jpg" Viewport="0,0,50,50" ViewportUnits="Absolute" TileMode="Tile">
</ImageBrush>
</Rectangle.Fill>
</Rectangle>
<Rectangle Margin="135,102,166.5,110" Stroke="Black">
<Rectangle.Fill>
<VisualBrush>
<VisualBrush.Visual>
<MediaElement Name="media" Source="Assets/video.wmv" ></MediaElement>
</VisualBrush.Visual>
</VisualBrush>
</Rectangle.Fill>
</Rectangle>