The proofreading of the kana is non-existent. E.g. on page 7, there's a duster labelled as a washing machine. On page 8, a snail is labelled as a kettle and a sprinkler is labelled a dustbin. I could go on....
The scenes depicted aren't well suited for teaching a non-European language. E.g. on page 5 there's a duvet ("kakebuton" = "kake" + "futon") and a bed ("beddo"), but no futon. What would you think of a book of English vocabulary that had the words "futon" and "bedspread", but not "bed"?
The artwork is pretty good, and the pictures are fun to look at.