From talking with people and my own (limited) experience, it seems that the ground can show up in a few different ways.
This is the groundless ground, that which everything happens from and as. It is the divine mind, God’s mind, Buddha Mind, Big Mind – itself distinct from any characteristics yet always manifesting in new and fresh ways as the innumerable forms of the present. It is emptiness dancing.
When the ground is in the foreground, it is obvious. Everything is obviously ground manifesting, the divine mind, emptiness dancing. There is no need to look for it. It is obviously there, in the foreground. This is where the realization of selflessness pops into the foreground as well. It is completely effortless. Just the divine mind effortlessly realizing its own nature.
This brings a release from suffering. There is an intimacy with all phenomena from the absence of I and Other. There is doing, yet no separate doer. The activities of our human self are clearly and obviously revealed as the spontaneous activities of the divine mind.
The ground can be in the background in at least two ways.
:: Realized but not popped ::
For me right now, it is there when I look. It is clear when there is a noticing of it, as selflessness is clear when it is noticed. But it is still more in the background most of the time. It even allows for temporary exclusive identifications with my human self and its contractions, although these tend to be more short lived and transparent.
This is a middle ground. Our habitual sense of an I is still there, and sometimes clouds over the realization of selflessness. The realization is also there, although not yet complete. It has not yet popped. We are at the other shore, but go back and forth between stepping on the shore and staying in the familiar boat. The sense of importance is sometimes placed on content, and sometimes on ground and content equally.
:: Not realized and unimportant ::
If there has been no discovery or realization of selflessness, then the ground shows up as background in a different way. It is still there, but is seen as completely other, as an irrelevant background. The (back)ground has little or no importance, and the content has all the importance.
I and Other
So one way of looking at it is through the lens of I and Other.
When the ground (and selflessness) has not been realized, it is completely Other and irrelevant. When it is realized to some extent, it shifts between being I and Other. And when it pops, it goes beyond I and Other – it just is, as all there is.