uGUI Image component not auto-generating mesh around sprite?

I made the assumption that, like the SpriteRenderer, that uGUI's Image component would automatically generate an optimized mesh around a mesh with transparency. It does not appear to be the case. Is this intentional? Is there a way to get it to do so?

I am using Unity 4.6.3. I come to ask this question because my Google-Fu is failing me.

Thanks!