How do “comparing to” and the general time frame settings interact?

When using the “comparing to” function in reports, the data doesn`t seem to be actually filtered by that. E.g. i selected “compare to previous week”, and i still see data for a month. On the contrary, when i change the time range filter from 30d to 7d, the data seems to be effectively filtered for the last 7 days - which somehow contradicts the “compare to previous week” idea.

Any insights on how to effectively use “comparing to”?