Translation:The new buildings are not low, but high.
"Short",when referring to a building, means length not height. "Alcsony" .would be "low" or "not high, not tall"
Except "low" would rarely, if ever, be used to describe a bulding in English. So is the app looking for a meaningful translation that makes sense to an English speaker or a transliteration that makes no sense? I see this app struggle with this issue all the time.
I should say "american english". Maybe Brits use low and high in this sentence. In America, this would literally mean a building built on low ground rather than high ground.
One normally uses short and tall to describe buildings in English, not low and high.
People do not describe buildings as 'low' in English. 'Short' should be an accepted translation.
Surely, "The new buildings are not low, but tall" should be accepted as a correct answer.