Yes it means exactly that
Saying that someone is strong... for 140lb
You're saying that they are not strong and that their weight is the only reason they come close. You're either strong or you're not. There is no stupid middle ground or justifications based on weight. It has nothing to do with absolutes either. Of course strength is relative to your size.
Is Liao Hui "strong for 69kg" or is he strong? Bear in mind that he is sticking most people here's max deadlift above his head
LIAO Hui (CHN)69kg World record 198kg - YouTube