Thousands of early childhood education centres around the world use digital documentation platforms to report children's learning. Yet there is little research into how these platforms are changing work practices in early childhood education. This pilot study tested the usefulness of cultural-historical activity theory to analyse work shadowing observations and follow-up interviews with seven teachers across four centres in Australia and New Zealand. The use of Leontiev's 'hierarchy of activity' of operations, actions and motive objects was found to foreground two actions -- "tagging" and "monitoring" -- that connected basic technical operations with motives for the use of digital documentation platforms. The article reflects on the potential of this theory for future research in digital documentation in early childhood education, and suggests areas for further research, including the emergence of datafication in early childhood education as a new mode of governance of educators' work.