Instead of lines why can’t the paper tests just be replaced to show “pregnant” or “not pregnant”. Even replacing the lines with a single character like “+” or “-“ would avoid the need to have tests in multiple languages.

Solves the problem of e-waste and eliminates any ambiguity relates to the interpretation of the results.

Almost seems like this is a case of intended over engineering for the sake of justifying a more expensive test. Or maybe, the “geniuses” at the top made it a mandatory requirement that the paper test cannot be modified in any way and must use a digital reader mechanism to interpret and output the results.

tl;dr: digital pregnancy test only uses digital tech to scan a standard paper test, and display the result, at 4x the price.