I wasn't sure if the word "Session" in the title of Roberto Giobbi's excellent column indicates that its contents are meant for discussion, dissection, etc. more so than the rest of the tricks in Genii, but in any event that's what the forum is for, isn't it?
The thing that stops me about Mirror of the Mind is the choreography. First you remove the wallet with the card and the holder with the mirror and show them. Then you put them back in your pocket. Then a card is chosen. Then you remove the wallet/card and holder/mirror from your pockets again. Why did you put them away?
Mr. Giobbi addresses this point: "Although placing the mirror back into your pocket is not absolutely necessary, it jusitifes the fact that you replace the wallet in the pocket." The mirror justifies the wallet, okay, maybe. But what justifies the mirror? Putting away both items only to retrieve them moments later is not, I believe, worthy of Mr. Giobbi's usual high level of craft.
The problem seems to me to be the type of wallet. I'm sure Roberto is right whan he says the Ed Balducci wallet is the most versatile type of wallet for the "Card to Wallet" and the best for table hopping.
But not for this trick. For this trick the Mullica wallet, which can be left on the table and loaded out in the open, would seem clearly superior.
However I wonder if it would be even better if you keep the blank card in the same holder as the mirror, and don't put it back after you show its reflection is blank.
What if you show the blank card in the mirror and put both down to your right. Have a card selected, control it to the bottom, and steal it in gamblers cop. Now pick up the blank card in the right hand and put it in the left hand, so the right can pick up the mirror into place, adding the copped card underneath it.
After the audience sees the selection in the mirror, cop away the selection and toss the blank card to the side. As a bonus, if the audience dives for the blank card, it is clean.
With this method you can change the presentation slightly; show the blank card freely before and after, it only looks like the selection when it's viewed in the mirror.
Or how about this; let a spectator freely cut a face up (stacked) deck and remove and hide their selection. You learn the selection's identity by seeing the top card of the face up deck so that while you are removing the mirror and blank card from your pocket you also pull a duplicate from a card index. Now the spectator freely selects a card which you never touch and which they never relinquish the trick still works.
Think about the effect, as Richard Kaufman once wrote; it might just be worth the work.
Finally let me just say that I hope this is not taken as a criticism of Mr. Giobbi's work. It's still his basic effect which provides the bulk of the mystery and entertainment in this trick. My suggestions are only made to streamline and dramatize Roberto's excellent foundation.