They're Not Drapes - They're CURTAINS!

I have no issue with Americans using different words for things than us. I do not even get riled when they spell "colour" without a "u" or "through" without ...well... most of the letters. I do, however, mind when advertisers start to use American English for no apparent reason in British adverts.

Coffee Mate have launched a range of flavourings for coffee - such as vanilla etc. 

In the advert for these, we are treated to a woman selecting her preferred flavour from three somewhat camp characters. Her choice of "Classic" seemingly delights them as it "matches the drapes." No it does not - drapes in English are cloths hanging from the wall/ceiling, while he is clearly referring to the curtains.

We are not American and do not speak American English - why does this English advert do so?