"Subtle cues" refers to small, often unnoticeable signs or signals that convey a message or indicate something without being obvious or direct. Full definition
And even if you think you don't really notice the fabric you do pick up on subtle cues like how it drapes and the texture. (whenthegirlsrule.com)
We learn to move slowly, discern between emotional hesitation and physical limitation and listen to subtle cues of both body and mind. (johnscreekyoga.com)
You will have to learn to read subtle cues that your dog is giving and using these to your advantage. (midatlanticbullybuddies.org)