Ian Jelf writes:

In fact, during training I was admonished for suggesting people
look both ways from the bridge as we crossed it in a coach!

Because you can't expect people to do two things at once, or at least
not *look* at two things at once. You should choose one item and then,
if there's time, the other. The "correct" technique is to describe
the "TVP" (Total Visual Priority) first and then go onto other (perhaps
equally or more interesting) things. If you don't do this, then people
will ignore what you say as they look at the TVP.

It appears that the actual rule is that people can't be expected to look
at one thing and listen to the guide speaking about another. At this
point it becomes tempting to make a crack about the sort of people who
take guided tours, but that would be a cheap shot, I guess.
--
Mark Brader, Toronto | "A good programmer is someone who looks both ways
| before crossing a one-way street." -- Doug Linder