What observationally induced effect can cause a highly elongated galaxy to be erroneously classified as E0?

Answer

If the elongated galaxy happens to be pointed directly toward us (face-on).

The visual appearance is heavily influenced by orientation; if an elongated galaxy is oriented such that its longest and shortest axes project nearly equally onto the plane of the sky (viewed face-on), it will be classified as E0.

What observationally induced effect can cause a highly elongated galaxy to be erroneously classified as E0?
galaxieselliptical galaxiesshape