I wonder, could it be the age and size difference that is what doesn't look right.
From the San Jose Nest Diary 2010:
April 16, 2010: We have three babies that are six days old and one that is three days old. The smallest one requires less food than older siblings so will not require many bites to grow. Given adequate food delivery to the nest ledge, all will do fine.
Parent is partially off the chicks and looking around, perhaps partner is due for feeding time? There is one chick in front less active than the others, but otherwise it is a squirmy chickpile. The cam is being zoomed is right now.