It's a visual metaphor/reminder for the message the series has been selling from the early days of season 1; no one can do it all themselves. Chrysalis might have power, but in the end she's all alone. Even in the alliance, she never had the trust of Cozy Glow and Tirek, nor did they have hers. They might've been working towards common goals, but it was all biding time while they waited for an opportunity to stab each other in the back so they can assume power for themselves exclusively. Rarity and Spike, as well as the rest of their friends by comparison, have each other's back and in the end will put the good of the whole over their own well being.