This is evident when I show what handwritten Japanese (Kanji only without any Kana) looks like, they still mistake it for Mandarin (due them being logographic), the same applies towards google searches too, as when I type a Japanese word in Kanji (despite having the UI and browser set in Japanese or English) I still get results in Mandarin since all the websites contain the TLD .cn or .tw when I am looking for Japanese websites ending with (.jp).
If a person is clueless about distinguishing the differences between languages (especially ones that look similar when written even though they're different, kind of like when writing in French & English but they're still different languages), then they fall into the trap of "Is that French?" or vice versa for example, when in fact it's written in English. Does this word all look the "same" to you or not when telling the difference between 日本語 or 中文?.
You get the point, I still get comments equivalent to "is that Chinese?" when there's kana present within the sentence (which Mandarin does not have, as they write entirely in Hanzi). Some words are written the same but pronunciation is very different as they're unrelated languages. Does the same thing happen to let's say Norwegian & Danish (or any other European language) since both pairs use similar alphabets and have an identical writing system?
From Japanese or Mandarin, there are characters that look the same but have different pronunciations altogether like:
| - | 日本語 | 中文 |
|---|---|---|
| 擲弾兵 | てきだんへい | Zhì dàn bīng |
| 艦隊 | かんたい | Jiànduì |
| 陸軍 | りくぐん | Lùjūn |
| 神社 | じんじゃ | Shénshè |
| 地獄 | じごく | Dìyù |
It's the logographic nature of the text that makes it more common in eastern languages. Modern Western written languages, for the most part, are strictly alphabetic so since the symbol doesn't represent concepts, only vocal Phonemes which when strung together represent a concept, it's really hard to misinterpret the symbols, and it really doesn't matter which language you're representing with them. This gets a little fuzzy in Celtic languages because they have a lot of sound combinations that don't exist in other languages, and there's some confusion at times when looking at Western script and Cyrillic because while they're both rooted in the Latin Alphabet, they both evolved separate ways of handling various sounds, but since similar words that share a common meaning (and often a common root word) in a lot of languages do in fact sound different, they also are often spelled differently enough that it becomes obvious quickly which language you're using. There are of course some words and short phrases that do in fact get written identically in multiple, closely related languages, and that can confuse machines and people, but it's far less common than with eastern languages.