I was happy to receive the official explanation by tracksetter Jody. You can read the original question, and some attempts at solving it, here: Picnic table puzzler
Jody says: “There is no table lifter on this Pisten-Bully, although sometimes when a table is frozen in to the snow it needs a little nudge from the big machine when a kick is not enough.
My personal method is to get out of the cat (which is really needed every couple of hours to stretch the legs and get in to the fresh air), roll the table over once or twice, and then groom out where the table was sitting. If it is convenient to return to that spot on a subsequent pass then I let the snow set up for a while until I return.
A couple of the rest areas on Pocaterra are wide enough, and also backed in to (not convenient to return to) so I groom beside them, move them right away and then clean up the site- these tables usually alternate sides of the sight from week to week.
If I am going right by the sight again, as on Tyrwhitt on the night in question, then next time past I get out and roll the table back in to place and erase the evidence. So that is twice per table times five tables on that particular night. Except I only moved two of them that night. All that grooming for one shift would be pretty much impossible in the best of snow conditions but with those icy conditions over 18 hours were spent grinding away at the surface of the trails to complete the South end.
Remember that there are at least two of us (usually three) that may do the grooming in PLPP. That is why the Live Grooming (it can’t actually be live in PLPP as there is no cell service but it is pretty close) did not initially show some of trails that were groomed that night- the snowcat hand-off happened around midnight and Upper Lake Access trail was finished up around 9AM. Holmes has solved the mystery, but I thought I would make it official. Happy Trails…”