Professional edition only!
When enabled new log rows added to a currently displayed log file are automatically loaded and displayed in the Log rows grid when they become available without the need to refresh the view manually.
However IIS flushes the log file only every minute. So if the application is installed on the web server new web requests will show up at most 1 minute later after they took place.
If the web server is on a remote server and log files are synchronized with When loaded as periodicity, a synchronization will take place every two minutes while the log files are loaded and new log rows will show up quickly after every synchronization.
Once new log rows are available statistics get out of sync but you can refresh them if needed with the link Refresh statistics displayed above the Statistics panel.