Without question not for takeoff or landing, it's not allowed.

I don't have experience in the bulkheads in Y recently, but I sit in bulkheads in J all the time (where I am sitting now as I type this!), and sometimes have stuff on my feet during the flight - absolutely no problem. I don't see why Y would be any different

But I see from Aerolopa 59A is an exit row on 35K, which is what CX uses to ORD (a350-1000). Seeing as we have quite a long taxi right now, I had a little fun searched through Cap 448C, which I think is the relevant text, in part 46 (2). It states:

"Whenever an aircraft to which this Article applies is carrying passengers, every exit therefrom and every internal door in the aircraft shall be in working order, and during take-off and landing and during any emergency, every such exit and door shall be kept free of obstruction and shall not be fastened by locking or otherwise so as to prevent, hinder or delay its use by passengers:, Provided that:"

(The "provided that's" I don't think are relevant for this)

So my interpretation is technically it could be allowed during the main section of the flight, per the law. But as to whether the FAs will permit it, or there is another rule I'm missing (whether HK law or CX policy), I'm not sure. And also, it could easily be interpreted to mean that having it there during flight would prevent it from being unobstructed during an emergency, as the law requires.

(14 minute taxi and counting!)