They are for aesthetics and do not light up. Don't worry, you're not the only one to think they should light up. I've answered this same question probably 5 times now lol.
I remember another reader actually did make them light up, and posted pictures of the results. But it took a considerable amount of work to disassemble the headlights (including baking to soften some adhesive seals), remove the decorations, install real LEDs, and bake the whole thing back together. It wasn't a task for ordinary mortals.
Oh yeah, I have a friend who mods headlights to make angel eyes out of projector beams in any housing but the work involved and willingness to do the work is alot. Like anything, anything is possible with enough time, talent and of course money. Simple answer to the question was they are just there for aesthetics.
I swear they light up on the AT Package (LED's)... I remember looking at mine the other week and there was this like notched or "check mark" LED glow pattern along the top but it wasn't on my wifes 2011 level 4... I'll look tonight when i go home...
On the Advanced Plug-in Prius or the Prius Five with LED headlights, there are LEDs for the parking lights. That is not so on the Prius two, three and four or the Prius Plug-in base. Two different headlight housings, two different parking lights.
Here, let me show via pictures the difference. Incandescent parking lights: Starting 2012 on, the parking lights on a Five or PiP Advanced are LED like this:
Mine only light up with the headlights on. They don't serve as DRLbecause we already have a set in the lower bumper.
It took me an entire week of going crazy trying to figure out what was wrong to realize that those LED looking decorations didn't actually light up. I don't see why Toyota just didn't make them LEDs. The holes are there. It would be so simple. I thought all new cars had automatic DRLs until I got my Prius IV.
