You can now run one population and one question against two dates and see the movement side by side, rather than opening two runs and doing the subtraction yourself.
Why it is useful
Because only one field changes, the difference is attributable. Move the date across a fee increase, a price change or a season, and what you see is that event’s effect rather than the combined effect of everything you altered.
Where to find it
Ask the agent to compare dates in chat, or open a completed run and add a second date from the run header.