Question about a Locomotive Feature

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The third photo down shows 49-inch-gage Hecla & Torch Lake 2-8-0 camelback named, “Manitou.”

What is the detail showing on the front of the smokebox? I am referring to the six dark block shapes in a circular pattern around the plate with the star.

It appears to be a rotating draft damper like what is used on some wood-burning stoves. If so, the dark block shapes would be openings into the smokebox. However, it may just be graphic design painted in black.

But if it is a damper or vent with openings, what would be its purpose? I have never heard of any smokebox feature like that.

Lending further evidence that it actually is a rotating damper is the appearance of two rods or cables attached to the top of the ring with the dark block shapes. Each cable runs off to each side of the boiler.

If those are cables that turn and run back along the boiler to the cab, each one could be pulled, which would rotate that smokebox ring either clockwise or counterclockwise enough to open or close the damper.

Does anybody know what the feature in the photo is? Are there any other examples of it?