When your weaving the rim on, your catching the first few rounds of weaving in the binding and it keeps the rim on. Many basket makers will put woven seagrass as a stuffing between the two bindings on the rim instead of the half round cane to hide the top of the basket weaving. Whenever you see a gray colored reed it's reed that has been over soaked.

What about the pins that go in the rim? I've always seen pins but here I didn't see any.

You want to make sure you don't soak your cane for too long or it will turn the dark gray and look off color from the rest of the basket. Also you can put a sealer on the outside of the basket but should never put it on the inside, so you can put mineral oil on the cane so it will last longer.