>>>> I can't really say whether it's better or worse, with visible-bell t 
>>>> on Windows the frame briefly flashes (with the FlashWindow function), 
>>>> a bit like a flash in a terminal.  Among the three visible-bell t 
>>>> behaviors, it's the best one IMO, in the sense that it's visible and 
>>>> not intrusive.
>>> 
>>> Is it possible to replicate on other systems?
>> 
>> It would be useful if someone could post a screenshot for those of us 
>> with no access to any Windows machines.
>
> I tried to do that, but it's not possible, it's a dynamic effect.
>

I tried again; see the attached screencast.