Translation:I want a different bag.
Having to translate this physically pains me. I was taught, very emphatically, that while ちがう does mean different, it also carries the connotation that that difference is a bad thing. We were taught to use "Hoka no" to indicate wanting something that was different (with no value judgement attached).
Also, yes, ほしい translates to wanting. But, again, we were strictly taught that it is a very childish and grabby wanting. And we were strictly trained to use "kudasai," "adjective-tai," and "onegai simasu" to ask for things, ever.
So, yes, you have a grammatically correct sentence that someone, somewhere, probably uses, but based on how I was originally trained to speak by native Japanese speakers, I am having an extremely difficult time accepting that this is how this program is choosing to teach others how to speak.
I think hoshii is only childish wanting if it is said by a child instead of o kudasai.
Hoshii just means that's something you like to have, but not something you use in a store to say I want this or that.
That's at least how I understood it.
I also assume that Hoka puts the emphasis on another why chikau emphasizes the difference
I instinctively turned text on to test-type "That's not the bag I want" and would also like to know this. From what I heard the speaker say and the image that formed in my head, this is exactly the kind of thing I would expect to see in a translation.
"I want a different" would actually give me a slight eyebrow raise watching a show, it just feels like we are adding too much meaning and intent that isn't really there, as has been mentioned in this thread.
wrong one + bag I want -> not the bag I want ?
Maybe it needs something that gives the phrase negation?
But I'm still learning. Could it be that subtitles usually lack in interpretation in shows? Usually doesn't feel like that though since it pretty much pops out when they are horrible as the sentences will make very little sense because they will often miss idiomatic expressions and metaphors.