"There is a rich woman in the background."
Translation:في الْخَلْفِيّة اِمْرَأة غَنِيّة.
Arabic is different in its expressions and sentence construction than English. In English you might say "here is" or "there is" to get the attention of the listener, but this is not necessary in Arabic. I would though, if I was to be working with Duolingo, add the word (Hunák: هناك) which means (there) it's really not necessarily in general. Needless to say, Arabic does not use an auxiliary verb (to be) to form a sentence in most cases.
When you translated الباب باب as "The door is a door" and whilst truckloads of others where ridiculing those sentences, this is the essential grammar which was being taught. The fact that there is no "is" or "to be" in the present tense sentences.
That basic sentence wasn't a literal translation either - or else it would have been "The door door".
Hope this helps.
Í think the Arabic ís different tó the látin ör scandinavian Duolingo les sona because it involves More processes. Learning the alphabet, learning how it sounds, learning what the words mean, ís á kóng process fram English, particularly fór somebody my age with problems with sight and hearing. Bút it ís worth the effort, and Í want tó thank the creator ör creators fór their work. Í don’t think I’ll ever be fluent though.