As he mentions in another post, the piece is essentially a 1x1 plate atop a headlight brick atop two 1x1 plates. But the headlight brick would have no stud on the side, just the square in the back. From a geometry perspective, there's nothing new to see here. Anything you can do with the hind end of a headlight brick can be done. But if for some reason you need that three and a half part connection to have some strength without a recessed side stud, well here it is.
A big difference from the headlight brick is that there is a whole lot more plastic below the anti-stud (or tube side, says TLG). Headlight bricks have a tendency to crack. I'm wondering if this has anything to do with the location of that portion of the brick in relation to the pip. If the plastic is injected at the top of the solid stud, then it will flow around the square portion of the mold and meet in the middle. Theoretically this should be fine as the already molten medium will bind together. But that's theory. Another theory would state that by the time the injection gets around the chilly metal mold it has already lost some of its viscosity and binding properties. But I would think you would need several more seconds for that to become a factor. The Emmet Brick has an extra 6.4mm of ABS wall below the anti-stud that should relieve that problem. I'm sure hoping that hairline on my Emmet Brick is the shot pattern.
One application I could see is when you want an anti-stud facing sideways and you don't want to deal with a bunch of SNOTtery. The headlight brick will give you the same function unless you have another layer of pieces just inside. In that case the side stud of the headlight brick sticks out a little farther than the lip of the brick. An interior conflict will ensue. Certainly not a difficult one to resolve though.
*SPOILER ALERT*
In the movie this piece was actually a Kragle cap. This piece does a fine abstract job of representing that. However I think a red axle connector would look a little more correct with better dimensions and texture. But getting that piece to stick to Emmet's back in a non-destructive way would involve a little more creativity. Or a new part.
