Yes, it is your brake lining wear warning light
Your struggle with interpreting the simplified shapes reminded me of a funny story from when my girlfriend and I were driving our used 300E home for the first time. She's in front of me driving a car she's only driven for a short test drive before. We're pretty nervous about the condition of the car, because we got it real cheap on an "as-is" basis. I'm following her in my Jeep.
My cell phone rings, and its my girlfriend in the new 300E. "A warning light just came on", she says. "What color?", I ask. "Yellow". "What does it look like?", I ask. There's a long pause. "It's like a circle with a little thing on top and lines shooting out from it." I'm still puzzled. We're both thinking what it might be (but she can look at the light of course).
So then she blurts out... "I know!! It looks just like a little hand grenade with little explosion lines around it!!"
(we pulled off at the earliest opportunity, and consulted the manual to learn that the "hand grenade" was actually a representation of a light bulb (base up, globe down) and intended to indicate a lamp out somewhere on the vehicle. Myself, I liked the hand grenade theory)