Not exactly palm reading. The blind man can not see the visible lines on your palm.
A man with no vision has no way of seeing your skin color, eye twinkle, hair style or that stain on the front of your shirt, so you’re in luck because your character is not judged by first appearances. You may have appearance but you are not invisible.
Lenny’s hand-holding, hand-reading is his quickest way to get to your character. Biometric identification. Your character is assessed on the basis of your skin texture, bone structure, firmness of grip, length of fingernails, quantity of rings, bracelets, and watches. He knows if you grip a hammer all day, wash dishes, use skin lotion, or file your nails. He knows if you wear a solitary diamond ring and Rolex or a plain band and Timex. And if he has met you before, he knows if you are wearing a new piece.
If you are introduced to Lenny, he will expect one or both hands. He will hold your hand longer than most people engaged in a shake. If he gets your hand or hands in his, expect to feel his fingers climbing up to just above your
wrist. Your character is most completely assembled by a double two handed read, first the right then the left if he can get it. Expect a read of both sides of each hand from both of his.
Lenny registers if you return a squeeze or pull away before he has gotten a picture of you. Lenny knows if you are a hand holder or not. And why not present your hand and yourself.