Tile image does not contain an Image field. Your image is a child of TileWidget.
In TileWidget make sure the image is set as public (the default is public - it’s a checkbox named “Editable”)
From TileWidget drag the blue wire and select GetMyImage (If inside the TileWidget the image is called MyImage, like you di with TitleText).
On this new node call setBrush
What set? The question was about changing the way the Image Widget is draw. The problem was that the widget takes a brush, not an image asset.
If you want to cache the brush (just guessing here), you can “put into the set” by connecting the brush to the add operator, there is no need for an output on the widget method