Apparent Suspension of Gravity

[NJV]

Look carefully. Of course, the box isn't floating, but it's only barely supported.

Is there anything more than just the friction of the box against the shelf that's keeping it from falling? This was my first impression, but despite the lightness of the box I have the feeling I'm missing something. The box is pushing straight downward, and the plastic covering it is quite smooth, so shouldn't it slide off?

 

[kyiydnlm]

you need to show us top end of the box.