Kelly Grayson: This is going to sound like I'm talking out my ass.
Isaac: Then please try to enunciate.
Old Wounds - S1-E1
[A banana is reduced to a shrivelled husk.]
Ed Mercer: So...it's an anti-banana ray?
Kelly Grayson: It's really interesting.
Ed Mercer: We need no longer fear the banana.
Kelly Grayson: Does it work on all fruit?
Ed Mercer: What about salads?
Old Wounds - S1-E1
Admiral Halsey: We would have offered you a command earlier, but you haven't really inspired anyone with all that much confidence this past year.
Ed Mercer: I know. I ha... I've had some personal stuff that's been going on. It's not really worth getting into. Can I have one of these mints?
Admiral Halsey: Those are marbles.
Answer: The book "Flatland", which is mentioned in the show, is a real book that may answer your questions in full (it's the story of a 3-D being experiencing the 2-D world and the 1-D world). In the 2-D world, there is no height, so there's no way to slice anything in half (horizontally). A being living in the 2-D world sees any object or being as a line (it's messy, but the lines have thickness, just not height, but all thickness is the same). So if the Orville was seen, it would only be seen 2 dimensionally and be seen as a line and others beings could just move out of the way. While there were buildings in "Flatland", perhaps this world doesn't have any, or the Orville didn't bump into any. There is death in "Flatland" when a being isn't careful and is poked, but these are usually by lines and triangles and the Orville would more like the circles and not in danger of poking anything.
Bishop73