Initially I got Funny Faces on the Farm for my 20 month old niece as a fun book to help her identify farm animals (most of which she knows already). We could hold the book up to our faces and ask her what noise the animal makes. The book works great for this. Whether she wants to do it or get one of the adults to, each person can see through the eye holes and be able to hold it up with the cut outs at each side. The spine of the book does get in the way of your nose but it's not too much bother. You do need a mirror to hand though for the child to be able to see which mask they're holding up.
The farm animals include pig, mouse, chicken and cow. Each brightly coloured with friendly faces and bright coloured backgrounds usually with a little extra character (cheese, worm and butterfly) to ask additional questions about. Each character has a friendly face to it and their pop out noses/beak bring them to life.
The back of the book says it isn't suitable for children under 36 months which I think is a little old considering the simplicity of the book (although it is because of the pop out noses). My 3 year old nephew does like it though and we tend to play a slightly different game with him by asking him to give us clues as to which animal we've got after opening it at a random page. It doesn't hold his attention for long though with only 4 characters.