Continuity mistake: Lt. Malloy has his lower left leg amputated in Isaac's attempt at practical humor. When they later find the leg, it's not just a lower left leg, but an entire left leg (upper + lower). So either Malloy regrew half a leg in the course of a single night, or they forgot to tell the prop department to only make a lower leg. (00:26:35 - 00:30:20)
Continuity mistake: When the crew is working to disable the device helping Pria to hijack the Orville, the Chief drills a hole and creates a great deal of metal/material shavings on the top of the device, which disappear. The device is also aligned differently in respect to the components of the Orville's circuits from the Chief's drilling shot to Isaac's probing shot. (00:34:21)
Continuity mistake: The remote control device installed into the Orville's circuits is shown several times through the episode. When Isaac is beginning to send his leads into the device the corners of the right end of the device are about 1/2" - 1" past the intersection of various block shaped components of the Orville's circuits. However, just moments prior, when the device is shown in place in the same circuit, the corners of the right end of the device line up perfectly with the corners of those same block shaped circuit components as evident by the slivers of light shining between the very thin slit formed where the two sets of corners align. (00:34:15)
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