Actually, only bids 10000k or more by an individual market maker would show...so one could only bid unnoticed for a few k...if one desires to hide a large number of shares one would have to place an AON (all or none) order - these don't show on L2
in conclusion I think s.o. with huge AON bids might just have painted the pps down with a $13 sell (for a miniscule loss) in the (false) hope that some scared retailers sell chunks into the bid (and as a byproduct he would get hidden cheapies)....that won't happen here IMO!