Queen versus 9 in the hole card viewer -- Can a dealer answer?

No counting theory here. I have a question for a dealer.

I'm now the proud owner of a REAL blackjack table. Won't say how I got it or where it's from, but it's real. A used one from Vegas. (They're legal to own if you're not running a casino).

My question is this -- how can a dealer tell the difference between a Q and a 9 in the card viewer for the hole card? They look VERY similar -- I looked at every card in the mirror. For some reason, I have to put them in sideways to see them, and now I can't remember if that's right or not. As much as I play, I should know!

Is it hard to tell the difference between a Q and a 9 in the mirror, if my viewer is correct and the card has to slide in sideways?