I'm actually talking about this one
But thanks anyway.
The panel obviously wasn't there back in TNG, they probably considered the buttons on the "cobrahead" to be enough of control back then.
Then during DS9 they must have realized that it's not a really very ergonomic way of changing settings and added the sticker.
There's also this flashlight they added in some episodes, which completely obstructs the flipup sight so i added a screen as backup sight.