This article is part of a larger project focusing upon explanatory illustrations that children encounter in pre- and primary school education. The research questions concerned (a) how preschool children make sense of iconic symbols when placing items of refuse on illustrations of refuse bins in a sorting task and (b) what stumbling blocks they encounter when interpreting these symbols. Video data were collected with 30 children between four and five?years of age. From the children's verbal and non-verbal interactions, four different categories of sense-making were constructed: by material, by object type, by appearance and by function. Three stumbling blocks were identified. The first had to do with giving the symbols a different logical meaning to the intended one; the second related to what materials the different refuse items were made of; the third was being able to stick to one correct way of interpreting each symbol.