Those emojis help to highlight users who are trending significantly in either direction (up or down).
We calculate the change by comparing a user's current score with his/her score in the previous engagement period (so if you selected a 7-day engagement period when setting up your score, we compare a user's current score with his/her score 7-days prior).
We then highlight (through the magic of emojis), those users whose score trend has increased or decreased significantly:
🔥 = Score increase of 10 or more points
❄️ = Score decrease of 10 or more points