Could you help me understand the correctness of the sentence. display their goods in their windows
Intended meaning is that Department stores want to display their goods. How does in the windows add meaning to it.
Well, it means that they are going to display them in the small area behind the glass in their shop front rather than in a stand in a shopping mall, or in the park near their shop - or anywhere else for that matter. 'Display' does not, of itself mean 'in the window'.