Continuity mistake: Malloy's hand instantly goes from pointing at Captain Mercer to open in the next quick shot while they are in the Krill chapel.
About a Girl - S1-E3
Continuity mistake: While Captain Mercer and Commander Grayson are having drinks and conversing. Mercer holds his glass close to his mouth in the frontal shots, but the glass disappears in the shots over his right shoulder.
About a Girl - S1-E3
Continuity mistake: In the shuttle bay, Captain Mercer and Commander Grayson's distance between each other changes between shots as they watch Bortus and Klyden depart on the shuttle.
Continuity mistake: Throughout the episode Bortus and Kelly's uniforms change colour between blue and black and random points, most noticeable in the courtroom scene. (00:54:30)
Continuity mistake: The Xelayan in episode one has no eyebrows, and her nose marks are between her eyes. In episode 2 she has eyebrows and her nose marks are on the bridge of her nose.
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