Because I understand the meaning of the sentence. There is a difference between an accurate and literal translation, if I can demonstrate that I understand what the meaning the sentence is trying to convey than it should be correct.
"Whose bread is it?" and "whose bread is this" are pretty much identical but in my opinion the latter is more specific.
I agree there is a difference between an accurate translation and a literal one. I didn't say you had to be literal. I said you had to be accurate. Having encountered one or two of your other comments where you're complaining about being marked as incorrect, I simply don't think you're accurate.
You've basically acknowledged that there are two slightly different English sentences, one with a more specific word ("this") and one with a less specific word ("it"). Well, it's the same in Danish - there is a post in this thread a little above yours that points out that it's the same in Danish.
And if the Danish you're translating is using the less specific choice, it's simply not an accurate translation if you use the more specific choice in English. If you give the impression of pointing directly at a particular thing in English, that isn't an accurate translation of a Danish sentence that didn't give the impression of pointing.
"Whose bread is this?" means this bread, right here, in your hand or next to you. "Whose bread is it?" doesn't mean that, I could be referring to bread in another room.