I don't have a sample scene you can use, but here is some useful information if setting up an AR scene in Unity for viewing within STYLY.
Both Unity and STYLY use a left-hand coordinate system. The world origin for an AR scene (0, 0, 0) will be located wherever the user scans the ground plane when prompted inside the STYLY mobile app.
When designing an STYLY AR scene inside Unity, I usually place the main camera at (0, 1.65, 0) to emulate the approximate height of an average person's eyes. The main camera's rotation is set to (0,0,0) so that it faces in the direction of the positive Z-axis. On the main camera's "Camera" component, I enable the "Physical Camera" parameter and set the "Field of View" to 75 (which emulates the field of view of a mobile device) and the sensor size to 150, 69 (which approximates an average sensor size of a mobile device). This gives me a rough idea of what the user will see when they launch the AR scene inside the STYLY mobile app.
That said, there is a huge range of mobile devices with varying camera specs that can alter the way that a scene will appear, so this is only a rough guide.
I hope that helps!