The first time I had sex with Raven, when Jack said these words, it seemed like Jack's nudity had undergone a different movement and began to turn into this（I didn't carefully examine other sexual scenes and cannot guarantee that this action was not used elsewher

And I think Jack's right arm gives me a visual impression of an inverted nail clipper in this picture，cut the arm out by itself， I even think it looks a little bit like a knee(But this type of arm seems to have been applied to many scenarios in this game)，I specifically searched for some real-life images online, but they didn't give me that feeling...  (did the size of the picture here become too large?

By the way，what is the deep meaning of this conversation? Raven and Jack have had the following conversation:

"——That's a professional grade six pack." "——That joke totally didn't work." When I looked back at the scene, I noticed that Cath had said before that Jack has strong abdominal muscles(You got a hell of a washboard there.How's a bartender get so cut? Because our "washboard" means "flat body", which made me mistake the meaning when I first read this paragraph, thinking that Jack is relatively  thin), but this sentence sounds like Jack doesn't have any abdominal muscles

Or，as the literal meaning suggests, is Raven just jokingly praising Jack's abs as commodity grade?