Why put the stepper separator inside the toggleable content?

[devr52]

https://github.com/primefaces/primeng/blob/master/src/app/components/stepper/stepper.ts#L278

This is somewhat contradicting on how the horizontal separator works wherein it's not together with the content? I am trying to get the same line like in the horizontal, but this is impossible to do in the vertical view because the separator can only be seen when the step is active??