If you display a detailed report on your iPhone under Settings --> Screen Time, then you may discover an hourglass symbol, the meaning of which you may not yet be aware of.
In addition, the hourglass icon may be orange or empty. Here we have summarized the meaning of the hourglass symbol for you:
Hourglass symbol orange or empty - meaning on the iPhone
Every application on the most frequently used app list has such an hourglass symbol listed next to it.
The hourglass icon is empty This app is not limited by a limit. This means that the application can be used without restriction by the user.
The hourglass icon is orange If the hourglass is filled orange, this means that you have set a usage limit for this app. Apps that are marked with an orange hourglass are also listed in the category "Marked with Limit".
You now know what an orange hourglass icon stands for in the list of used apps under "Screen Time" on the iPhone.