Wow, thanks. I managed to get an emotive response, and from a DFer no less. I can now claim to be a legitimate artist.
I imagine the drawing as an engraving in Saiko's fortress.
The Ignominious Collective Failures of Responsibility
Engraved on the wall is an image of a cage, a child and a dwarf. The child is in the cage. The child is in the foetal position. The dwarf is idling. The artwork relates to the slow death of Urist McThirsty in the dwarven fortess Checkcages in the late summer of 945.
Would be nice, and maybe my dwarves would even repent when they saw this, but they certainly aren't
that artistically involved. Literally half of their engravings is about one minotaur, who killed that or another dwarven hero. They don't care about dwarven children dying in cages. Which is actually quite authentic - if they did care about the brats, they would be releasing them from these cages. But a lazy child is not a dwarven hero, and thus not worth mentioning. Masterfully prepared roasts on the other hand…
You only need 150 or a little more to be Ecstatic. Losing a direct family member is -50 happiness. Losing a close friend is around -30 or -20. Losing a masterwork is -1000/x, where x = total number of masterworks you've made in your life. I am not sure whether a stack of bolts counts as 1 or 25 on that x. I would not be surprised if your dwarf there took -1000 happiness because that one bolt was melted.
Just before melting one bolt, made by one of my Original Seven, the guy had happiness 123 (as seen Dwarf Therapist). After melting, 22 bolts remained, and the guy had happiness zero, since DT doesn't show negative number. So definitely one stacks counts as less than number of individual bolts it contains. But there are other divisors possible with bolts, like when melting (where every ten bolts counts as 1/10th of a bar). By the way, apparently not all means of losing masterworks are recognized by dwarves. Recently I was surprised when Forgotten Beast destroyed masterwork door, and its creator wasn't moved at all, he even hasn't noticed that.