Well, in response to the original question, no, the owner of the room in question has NO impact on the engraving, generally speaking.
If you have engravings of anything but the top two or three quality ranks, you will only get "shape" type engravings (the ones in the shape raw), or things that the engraver likes.
Engraver likes and dislikes (if they can be engraved - you can't engrave images of iron or microcline, but you can engrave trees or caps or animals) appear around 10% of the time. Note that if an engraver puts up an engraving of something that the owner of the room DISLIKES (which is common if both engraver and room holder dislike the same creature), then the owner of that room will HATE their room from then on.
You can, however, get some engravings related to the likes of other dwarves. I'm not sure about the mechanics of this, where if someone likes a given dwarf, or is close friends with them, they will engrave the things that dwarf likes (will show up as dwarf and whatever they like, typically these are animals, like a dwarf and their pets). If they don't have anyone like this, this seems to default to the mayor, so you'll likely see alot of the mayor holding up kittens or goblets or whatever it is they like. The owner of the room you are engraving has no impact on this, just who the engraver knows. This only occurs about 5% of the time.
The VAST majority of your engravings of higher quality, however, are going to be "Dwarf History" - and unless you have plenty of historical events to flood them out, you're going to see the overwhelming majority of your engravings be the election of the mayor or the founding of your fortress. These have nothing to do with the person's room, however.
My current theory regarding these histories is that there are a certain number of "history slots" that get defaulted to your founding and mayoral election. In order to get other historical events to appear, you need to fill those slots - the more history, the more slots that used to have founding or mayor elections in them get supplanted by other things.