I believe the current understanding is it's the same number of 'chirps/purrs' but they are in a scrambled order each time.
As in, I could re-write that sentence above and randomize the words, but it's still the same words. If I re-write it 10 times in one long string in random order each time I don't need a start or end point for each sentence, you can work it out based on the repeating number of unique words regardless of order - 'time' will appear 10 times, 'understanding' will appear 10 times, 'the' will appear 20 times, etc.
This is what I understood. Same number of each symbol in each iteration, but not necessarily in order.