Exposure means in movie making lingo ( What kind of an audience ( Age,Sex,and Culture Groups) and How big of Audience,wide spread) or just a (certain age group or culture group), But to get the right meaning the guy was expressing, We would need more detail of the conversation!

Example:

If you had explained the main part of the movie to him and it’s meanings, he may have asked you, How much ( exposure )are (you hoping )to ( get out of it)? The movie! Because may be( he felt )it wouldn’t draw as big of an audience that may be (you were looking for), or may be he felt it wasn’t going to be as big of a hit, Unless may be you did some big editing changes or what ever etc. and it could be, He felt the way the movie is now, it was only going to interest a small certain group and age! and he felt a concern, and that’s why he ask you the question!

May be if you had told him, how much exposure you were expecting or hoping to get from the movie!, he may have answered you back with, well a few changes (would have )to be made then to( grab a way bigger audience) to (attract all ages and cultures)!

it’s like the exposure of a camera, except with people being “light” and your movie being the “film” (no pun intended.)