No, that is not a tiny harpoon, it is actually a needle. The reflection of the metal from the camera flash distorted the needle shape.
Joining Tips: With most fibers, I find it best to join before washing. The big exception is chenille, but that is a story for another day. I have spread the two panels for photographing, but when I am joining I have the pieces stacked one on top of the other. It still amazes me to work folded, but then the weaving opens completely flat.
Always plan for a join to happen where there is a color change if you want the join to disappear.
Notice that I have brought one of the yellow warp ends from Panel #2 to be the first end in Panel #3. I discovered ( through painful experience) just how difficult it is to distinguish the warp from the weft when both are black.
When joining, I join pick to pick. I will sew through and join every single weft pick. It takes me between 3 and 4 hours to complete a join.
Again, I want to remind folks that this major project took me over a year to execute with lots of thinking time between each step.
I am really not that productive.