This is a very tactile book and quite heavy. I t tells two parallel stories. One is in normal prose. The other is told in black and white pictures.
The pictures to some extent work the same way as they do in a picture book for pre-school children; there is more story in the pictures, though here it could be argued it is a supplementary story rather than an extended story. The eye is drawn from left to right, from the top of the page to the bottom. Double spreads create drama.
The text is formatted raged right and this may suggest it is suitable for an emergent reader. However, if follows a normal story arc. The font has a serif and the difficult a and g.
It may also be suitable for the teen reader : it contains the themes of peer pressure and bullying. In these two stories adults let the protagonists down. The prose story includes a first person narrative and reads like a diary. The story in pictures contains a newspaper article. The reader needs to have a sophisticated level of understanding.
The first person narrative may also make the books suitable for young adults. There is a high emotional engagement with the girl who writes the diary. There is also a shock element: was Ella burnt alive?
Above all else, this is a beautiful book and I can quite understand why it was short-listed for the 2018 Greenaway medal.