Depending on which chapter you're looking at, you're probably right. What's going on is that each chapter is represented icon-wise by the chapters' boss. Where things admittedly don't completely make sense is that in some cases the boss fits the theme of the current chapter (e.g., Golfing Bear is the boss of Chapter 1: Leisure), and in other cases the boss fits the theme of the upcoming chapter as though the boss is guarding entry into the place where it belongs. That's what's happened in Chapter 4: Animals--its boss is Brainy Boss, which fits with the upcoming Chapter 5: People. (Then there is one chapter whose boss fits neither current nor next chapter--feel free to make up your own unofficial explanation for that one.)
In any case, we're probably not going to swap around the bosses at this point in the game's lifecycle. But we do want to acknowledge that: 1) your observation is probably correct, and 2) let you know that there is some logic behind which bear is used to represent each chapter, even though the logic is inconsistent.