I hope you do not mind some instruction here. If you do, I apologize before hand and you will let me know.
You chose a brilliant subject for your image all you needed to do is pretend you were a professional photographer and ask the shop keeper to help you. I have done some shots like this over the year and they work well when the easily moveable display is again a window with other displays to the side. Or, You carry a piece of black velvet cloth and get some people you do not know to hold it hold behind the display where it was. All you do is ask and people will be happy to help. I have loved photography for it has given me the excuse I need often to meet new and interesting people if only for a short time.
Happy New Year
Your comments and estimation are ok, so you don`t need apologizing. Of course I new defects of this picture. I was thinking a lot how to improve the background using some effect (e g at PhotoShop), and as result decided put it as is.
Thanks for advises.