>how to make the square

The gentleman in question made something rectangular(ish) with forefingers touching and the thumbs arranged in a decisive, yet gentile way, not touching as in an art nouveau motif. The orientation was diagonal, the little finger or pinkie slightly curled, so that the waitron would appreciate the calibre of the customer.

I'm so pleased at your concern, Faldage, are you considering making use of this method? I could fit you in for a formal training session sometime on my next world tour.