Customer support is one of the big reasons why certain stores can sell their items higher than stores that offer bare customer service. However, one thing is for sure: many service reps would tell you what you want to hear and sell you something even if it looks terrible on you. Sometimes, a sales rep may go out of their way to tell you it's not that great in diplomatic way and then deter you to another item they think will look better for you. Regardless though, the question is: do you prefer that the sales representative tell you honestly how the item looks on you or are you the ones in denial who rather receive compliments, even if it doesn't look good on you?
I would definitely prefer honesty. If something doesn't look good on me, I'd like somebody to tell me it doesn't look good on me, and I definitely wouldn't like anybody to tell me that it fits perfectly or something like that when it actually doesn't. And if a sales rep would tell me that a clothing item I planned to buy, doesn't look good on me, then that would be perfect as it would stop me wrong spending money on something I probably wouldn't wear that often. A lot of people, though, cannot stand negative criticism at all, so the sales reps have to be really smooth about telling a client that something doesn't look good on them. In my opinion, they should be taught how to do that.
I definitely want the sales representative to tell me honestly if the product looks good on me or not but in my experience I have had sales reps telling me that the size doesn't fit but never that the product doesn't look good. I think they don't usually say that the product doesn't look good on the customer to be safe from offending any customer.
