So something that might help a lot is the Cornsnake Morph Guide, which is now available digitally only. I will try to explain what distinguishes Terrazzo. Terrazzo originated in Upper Keys corns, so think of that typical coloration. Very hypo, no black borders, a creamy white belly (as opposed to other corns with the snow white belly), generally no checkers. Add the Terrazzo pattern to that. The stripe starts out as with a regular stripe, but breaks up and blurs out further down the snake (like vanishing stripe). So I think the answer you're looking for, how do we know it isn't a Terrazzo, is more by coloration, rather than pattern. Terrazzos have dark eyes. Amel stripes have red eyes. Terrazzos have a sort of speckling to their sides which is also not typical in stripes.
If you search on here for my Boot Keys that I sent to John Finsterwald, Phoenix and Scarlett, you can see what Upper Keys typical coloration looks like, without the pattern. Then, imagine that with the Terrazzo pattern added to it.
Then you could compare my snakes Loco or Zora, pinstripe Miami motleys, to the Terrazzo pattern. Miami has a coloration somewhat similar to Upper Keys, but again, you can see how although the pattern is striped, it is different from Terrazzo.