Yeah, usually a flex printed circuit (of Kapton, the orangy yellow stuff) plugs into the main board. It might have ~8 contacts and uses I²C interface. It feeds an IC mounted right on the flex that drives 50-100 axis lines. The end of the flex goes to the display and transitions to silver ink (which you can see) that transitions to ITO (which you can't see). You have your finger on places which are still silver ink, so it will work.
The Eink display itself is similar, but at a much higher density of 300 DPI. The capacitive touch only needs to be ~6 DPI since it can interpolate.
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