Most of these "trial lessons" are bimbles to see if the potential student likes small aircraft flying rather than a lesson as such.
I would disagree with this as well - for those only coming for what is really an air experience flight, this is fine, but anyone who looks like they are serious about learning the first lesson should cover "Effects of Controls 1" in sufficient depth to then be able to go onto and finish EoC 2 in the second lesson.