Dandruff is when your head under your hair loses little white flakes of skin and they get caught in your hair or fall onto your shoulders. Dandruff can be itchy like in the picture, or just not be nice to look at. You can buy special shampoo to get rid of dandruff.
Earmuffs can be for one of two purposes: first, to keep your ears warm and second, to protect your ears from loud noises. Warming earmuffs are usually soft and fluffy and are worn in very cold areas. Protective earmuffs are made mostly from plastic, and are worn by people who operate heavy, noisy machinery or work in very loud areas.
Something is fluffy if it is very light and soft. Plants like dandelions have very fluffy flowers, and some animals like long-haired cats and rabbits are fluffy.
Handcuffs are used by police officers to restrain people who have done or are suspected of having done bad things. Handcuffs are made from strong metal, and lock around your wrists so you cannot get your hands apart.
Something is rough if you touch it and you can easily feel all the little bits that make it up, and those little bits are hard and sharp. If you fall over on a rough surface you are likely to skin your knees. Some things, like sandpaper, are rough so they can be used to scrape the surface off something else. The opposite of rough is smooth.
You ruffle something when you mess it up so it isn't smooth and neat anymore. The bird in the picture has ruffled feathers. Ruffle can also be another word for a frill, although frills tend to be around the edges of things and ruffles can be anywhere.
Snuff is powdered tobacco leaves, designed to be sniffed through the nose. Snuff was much more popular in the past than it is today. Most people today smoke cigarettes rather than sniff tobacco. Snuff was carried around by people in their pockets in small, airtight snuff boxes, which ranged from simple wooden boxes like in the picture to quite elaborate and expensive jewelled boxes.