Wow, the body and eyeliner say girl, the top of the head and neck say boy. I would be very confused, too. It seems to me that we are seeing quite a few JR line chicks that are very pale and washed-out and ambiguous to sex.
I recently sold a little cockerel to a lady who had purchase CL Pullet chicks from a feed store (from Meyers Hatchery). She sent me photos of one of the three who is much lighter and the down is blurry--not dissimilar to your chick, certainly not obviously girl like the other two and it was sexed as girl at the hatchery.... If the chick were in my flock I would call it a male but I am wondering in the JR line if she did not emphasize down color since that is not something that is judged at show and the girls are frequently atypical. The older females seem to have stronger barring than what we have typically over here so maybe the barring gene in her line is strong enough to override the wild type down and ends up blurring out the stripe over the back of the head and neck. Bad for chick ID but good in the show ring?
If it were in my flock, I would mark that chick for future reference and grow it out to see what it ended up looking like. If you could do a photo essay on it as it feathers in and keep us posted, it would be most helpful and educational!