Juliet:
"What's in a name? That which we call a rose
By any other name would smell as sweet."
Romeo and Juliet (II, ii, 1-2)
I think the name is more about how you market the thing rather than there being a material difference. Some here will tell you that a Trail Lesson is ex. 4.1 whereas an Air Experience is ex. 3. I don't think it matters to us, maybe Trail Lesson to some people might appear to have something of a test or grading about it; not what they want from a gift! I think the instructors I've worked with and the schools I've worked at all treat it as an opportunity to get the participant back to do some more flying. Clearly, someone who is having an 80th birthday treat probably isn't going to (though you never know!) The flight I did today at first didn't look like a repeater but when we got back to the office he asked about making more bookings, so always try and convert. I've only very rarely had someone not take up the offer of trying out the controls (which of course they're not obliged to do, then it really is ex. 3, not 4.1!)
I think the important thing is NOT to market the flights as a 'Scenic Flight' or a 'Joy Ride'. When we get people ring up for a scenic flight, we say that it'll be an air experience flight over some of the most spectacular scenery in the UK (North coast of Cornwall). We usually get a sale.
TOO