The Multi-Troop Transport is the vehicle that deploys the battle droids in Episode I. Why anyone would want a microbuild of this none-too-lovely vehicle is beyond me, but whatever. :o)
This is the direction the ship is facing in the advent calendar picture:
But I'm pretty sure the calendar has it backwards, because this is what it actually looks like:
The taller part (with the circular hatch door) is in the front:
Here's a scan from my fantastic book, Star Wars: Complete Cross-Sections:
Interesting new fact from the scan: "...the MTT's face is designed to ram through walls so that troops may be deployed directly into enemy buildings..." However, MTTs have a maximum ground speed of 22 mph, so I wonder how forceful such a building impact can be.
More information about the MTT may be found on Wookieepedia.
Lego parts information for today's build may be found at Bricklink.