The Theoretical Ad-Like Thingy

"So there'd be like two guys in a park or at the mall of somewhere talking about normal stuff. And then something crazy would happen in the background and one of the guys would be like pointing but it would be the product. And there'd be some copy at the end that says something about how it gets noticed."
"Do you have a tagline?"
"Yeah, and there'd be a tagline."
"What is it?"
"I don't know yet."
This is a reenactment of the presentation of a theoretical ad. For some reason, students present these all the time in class. It wants me to poke my eyes out or, lately, want to poke their eyes out. There is a vague concept here, but this isn't an execution. It's like drawing the first gesture of a circle and saying "What do you think of my portrait?" I don't know. It's not a portrait yet. This concept above, I don't know. It's not a script. It's a vague notion about a script.
Do not present theoretical ads. Do not present vague paragraphs. Your job is not to create MadLibs.  If you don't know whether a spot should take place in a mall or a park or the international space station, pick the one you think is best. Create a concrete idea in the mind of your creative director or client (or instructor). Talk about options and alts afterward. But first help them imagine something real and specific.
Two things can happen when you present a theoretical ad. The first is that, because you haven't brought the idea to life, people don't get it or don't like it and the idea dies. The second is possibly worse. Because you have left the idea so open-ended, everyone fills in the blanks with whatever's in their head. Instead of everyone in the room seeing the idea as you envisioned it, you now have six different versions/visions of your idea populating people's brains. Which means that if you push your idea forward to the next stage where you do make it more specific, at least five people will think "Oh, that's not how I was picturing it."
Bottom line--be specific. If you've ever taken a creative writing course, this is something they tell you about your language: be concrete. The same is true here. If you're presenting a spot, present a spot. For a print ad, show a print ad. Not an ad-like notion. Or, as my instructor Coz Cotzias used to say: "That's an interesting thought. Now go do a fucking ad."