Game Of Thrones Season 7 Implications: What "The Spoils Of War" Really Means
2. The Lannister Attack Fall-Out
This was the most crucial moment in the entire war between the Lannisters and Danaerys, make no bones about it. Cersei losing the Tyrell gold and her means to pay off the Iron Bank effectively ensures that her options to increase her military might are now exhausted, not to mention the number of her army that were just burnt to ashes.
The queen now faces huge fall-out that should shape the end of the war, as the Iron Bank will do what the Iron Bank always does and will hedge their bets, removing support for Cersei and probably aligning with at least one of her enemies. Dany might be a wild option, but at least she might help them recover the Lannister debt (or she might destroy them for crossing the Bank, at least).
Losing the support of the Iron Bank is the final nail in the Lannister coffin, and it's now just a matter of time before Cersei concedes (there's no way she will, of course). That will either mean she'll do something rash (like burning King's Landing to kill her enemies - but also her people), or that she'll be more likely to talk to Dany and Jon about the far more pressing issue of the White Walkers (which she didn't have to do when she held all the power).
Interestingly, it was also disastrous for Cersei because Qyburn's much-hyped Scorpion is no more. Not that it really did a great deal in the first place, since even Bronn was unable to shoot the moving target in a fatal area.
Also, Bronn absolutely wins the entire sequence, not just for the exceptional hero sequence shot from his perspective (the best action of the entire show so far), but also for laughing cheaply at "Dickon".