I think he was referring to the “big players” seeing our stops
Which in all honesty, is a funny statement and partially true.
It’s not common knowledge that brokers aggregate orders into an average price and offset this against a total pool of buy and sells. If they have a net exposure they may well pass this into the market - hence where stops can be seen from a liquidity point of view (this depends on there own risk management policy)
A subtle difference, but correct in a sense.