I'll first drop the question and I'll explain the purpose after.
Does your Kobo Aura presents a shadow around the bezel (inside the screen) when frontlight is on?
The shadows are just like the ones shared in this thread:
https://www.mobileread.com/forums/sho...d.php?t=255074
I recently got my Kobo Aura replaced under warranty by a new one.
After trying the new Kobo, I noticed some shadows and I was intrigued about them because I didn't remember at all seeing them in my first Kobo. I googled about it, found the thread I mention above and taking in consideration the opinions in the thread about the shadows not being considered normal (mainly the opinion from Anak), I decided to return the Kobo back to the store. They accepted my explanation and gave me a new one - no questions asked.
(Before I leaved the store, I remembered to check the Kobo Aura in exhibition and it also presented the shadows
).
Unfortunately the Kobo they gave me presented the same shadows around the screen and honestly I was almost by then questioning if my first Kobo had the same shadows but I never noticed them...
Fortunately the thread above reminds me that I'm not suffering any kind of hallucination and there must be some explanation.
Now the thing in common about this "shadowed" Kobos (which differentiates them from my first and "clean" Kobo) is that they all came with factory 2.8.0 firmware installed (even the one in exhibited in the store, which I checked), whereas my first Kobo had the 3.15. So maybe this could indicate that they fixed this issue and the most recent Kobos don't present this problem any more.
Or maybe it doesn't mean anything and I was just lucky with my first Kobo...