Houndstooth pattern on the zoom loom: warp and weft color changes every two threads. On the zoom loom, you have to wrap the weft around each pin, changing colors every two pins, and weave the weft with the needle, again changing colors as you go.

Photo-Tutorial
Starting from the bottom:

Photo #1: With color A, start at bottom left, and wrap around the first pin on the top, wrap around all three pins on the bottom.

Photo #2: With color B, start at bottom left, between 2nd and third pin on bottom, and go around last pin on top.

Photos #3-6: With color A, weave over and under, from right to left, go around first pin on left, weave over and under. Skip next three pins on the right, weaving over and under, going around the pin on the left and returning to the right side. Continue until 8 sets completed.

Photos #7-11: With color B, weave under color A, over color B, etc. starting between first and second pins on right. Go around pin and return to the right. Start between first and second pins going right to left, repeat until 7 sets are completed.