Outside of sci-fi (as in: in physics based renderings) wormholes look like lenses, and a lens free-floating in space with only point-like stars behind it is hard to notice.
ERBs in particular are unstable in a universe containing literally anything else including a single photon, so you can't ever see one.
Even though they had Kip Thorne as a scientific advisor and he made a scientifically accurate rendering of various environments, if they'd not made it a swooshy tunnel in the middle then the transit would have been somewhat boring (or sudden) cinema.
