Where'd the brake fluid go?

Sorry if this is long.
I've been around vehicles all my life and I'm a sensible guy, usually.
This morning, I was going over my truck in preparation for my trip to Raleigh NC.
I looked at my brake reservoir once, twice, three times and I could not see a visible level of fluid.
I can see the minimum line and the max fill lines stamped on the reservoir container.
It was early morning light so I turned on the IPhone flash light to take a better look, I see no fill level.
I try shaking my truck to see if I can make the fluid move. I see no movement.
So I go get a stool, step up un-snap the fill cap and try to peer in. It's not easy with the hydraulic hood rod in the way and the trying to look from the front is difficult as well.
But I try, and what do I see, some sort of funnel filter thing that prevents me from seeing clearly into the tank!
Now what? Oh, bye the way, breaks are working ok.
I call my local Toyota shop, mention all this and they ask me to bring it in.
They were so nice, I didn't have an appointment but they took me right in.
Explained the deal to my service writer and went and sat down in the waiting room.
About twenty minutes later, my service writer comes over to me and says "you're all set."
She goes on to say that the tech checked it out and the brake fluid level was where it should be.
But I can see it!
So what's the deal? Why have stamped marks lines on the container if it's too thick to see the level?
All other cars I've owned, the reservoirs have been translucent and I can easily see the level.
Anybody notice this or am I now legally blind?

 

I had no trouble seeing my fluid level on my 07 and and the same on my 14.

 

I actually was wondering the exact same thing the other day, then got sidetracked and forgot to ask while at the dealership... Hopefully someone knows what's up.

 

That little screen comes out so you can check your fluid if you want to look inside the fluid is clear and sometimes doesn't show up like we would like.