Translation is UX writing.
A successful translation should speak to the target user. That is, the translation should make sense to the reader in their language, so that the reader can understand the given instructions or be persuaded and motivated to act according to the CTA. Why, isn't this the fundamental principle of UX?
A good translator never translates literally, because we know how futile literal translations are in delivering accuracy and conveying nuances of the copy. Instead, we rewrite the copy in a way that speaks to and stirs the heart of the reader, just like how a UX writer puts herself in the shoes of the user when crafting her words.
Translation is copywriting.
For marketing collaterals, especially hardcopies like pamphlets and flyers, clients usually prefer to stick to the original design and change only the written content. A copywriter's skills come in handy at times like this. To fit into that pre-determined design, translators have to exercise creativity to create a new copy that is succinct yet retains and encapsulates the key meaning/s from the original copy.
From my experience, it is especially challenging when translating from Japanese to English, as the complexity of one Japanese kanji has to be broken down into several words when translated into English, lengthening the sentence. Copywriting skills are valuable to stay within the limited space the design offers.