The context of this wasn't about dekopin, though. Humans, particularly younger ones, can 'feel' when something is being moved near their forehead. There's a lot of possible explanation for this, including more bullshit-ish ones like 'third eye' but actually it's the sensation produced by the tiny, almost invisible hairs on your body that reacts to the air current generated when something moved close to your forehead. This, coupled with Abby who (after ancension) has the 'hole' was probably the inspiration of this...uh, 'slightly'? lewd art.