Anime Discussion

I was watching new episode of one piece and i I saw Luffy shocked after seeing joyboy’s haki but I don’t know why I think that Luffy was not shocked that how powerful joyboy’s haki is he was shocked because a robot was using haki and in the end we saw imu on his knees afraid and i don’t think that joyboy’s only haki can make imu on his knees it’s more likely that when imu felt joyboy’s haki he remember the fight with him and got PTSD form his haki What’s your thoughts on this?