I'm not a fan of this devotion here, as it seems to portray Our Lady as focused on herself, her loss of Our Lord's Presence, whereas every thought of her entire life was selfless, and the grief would have been focused on Our Lord's Passion and HIM, rather than on herself, as well as for the souls He had just redeemed, offering her suffering toward their salvation.
Our Lady wanted to do only God's will, and if it was God's will for her to be separated from Our Lord ... physically ... then she would not have give that separation a second thought. That's actually what the "Dark Night of the Soul" accomplishes in lesser saints (but Our Lady was in that state her entire life).
That's to say nothing of the fact that Our Lady was always spiritually united to Our Lord, and would not have longed to go into the tomb, as this describes, but knew that He was not there at the time, and she also knew and believed (unlike anyone else, being the only one left keeping the faith) that He would rise from the dead shortly. This makes it sound almost as if she was grieving as if He'd be gone permanently, i.e. did not believe in the Resurrection. I doubt that Our Lady was too desolate in this way knowing FULL WELL that Our Lord would shortly be back. She experienced a greater physical separation after Our Lord Ascended into Heaven, but of course she remained as spiritually united as ever.
Basically it suggests 1) self-centered focus (at least in its premise) and 2) lack of faith in the Resurrection, since she knew He'd be back very soon
Our Lady's grief consisted of recalling Her Son's suffering and where souls would be lost despite His Passion.