That head on photo shows a bit of a spoon at the end of the bill. Very cool! I've never noticed that before.
I pondered that too. I haven't decided if it is real or an optical illusion caused by a water drop at the tip. I have found no mention of it on the web or in my field guides. Scanning through images on the Internet give some hint that it may be real, but not conclusive.
Just before the tip of the Western Sandpiper's bill it constricts, then gets fat again.This bill is especially long, indicating a female, which are slightly larger birds than the males. Several shorebirds have this sexual reversal, linked to reproduction and care of young, such as it is. In this case, after the eggs hatch the females migrate and the males stick around the precocial chicks for a week or so. Then, they too, migrate south. Several weeks later the juveniles head south. That's why we, in lower latitudes, see migrant adult Western Sandpipers in July, and juveniles August-October.