Tell me please why an article was omitted in the following sentence before the word sense.
If you're an ace at picking out fabulous fabrics, accessories, and shoes when you get dressed each morning, you probably have (a) discerning fashion sense.
It is from Vocabluary.com. I am aware that the word sense can be used as a mass noun meaning a sane and realistic attitude to situations and problems (this definition is given by the Oxford Dictionary), but It seems to me it was used there meaning a keen intuitive awareness of or sensitivity to the presence or importance of something( by the Oxford Dictionary). Tell me please If I am wrong, and If am, then why?