Alright, well I have some things for you. First of all, I have no idea how much Exp. you have with RMXP. But the show picture command should be simple enough to use when haveing conversations. Even with long conversations. I would suggest useing a Common Event for your main Character(s). Basicly you could make a whole Conversation Event System, that would read who was talking and what and where to show the picture. But I guess it would be some effort to do so. Haha. I really like Event Systems, so yeah...this is something I would want to take on for fun (maybe I will).
But to be honest why would you do it with Events when you could use a Script, right?
I myself love this Script. Slipknot did a great job! It's very nice. It allows you to do exactly what you asked for. EXACTLY! Though I'd sumit, the pictures wouldn't be as big as the one in your Screen Shot. You could fix that though.
Basicly you have to import all the pictures you want to use into your Picture file. Then when you want to use the picture (BTW there are two options you have. In the box or out side and to the right, JUST LIKE YOUR SCREEN SHOT) is type \Pic[file name] in the begining of the message command box. I suggest that you type out what you want to be said, then add the \Pic[File Name]. Do not put any space between the code and your message. When you play your game, you not see the code at all and your message will look fine.
Here's the link to the topic inwhich I first went to a long, long, long time ago when I looked for a AMS. You'll note that there have been new Verisons of the Script, but to be honest, I perfre this one. Download the Demo, it will help alot.
http://rmrk.net/index.php/topic,256.0.htmlI hope I helped. I hope this is what you are looking for. Oh and one more suggestion. When you make a request, you should put that in your topic title. It really helps people. I first clicked on here thinking this was a new Script or System or soemthing. Also when requesting something, it's always nice to screach first. Because you might find it or something even better than what you want. If you did search, you should tell us and where you did so, that way we're not searching in the same places and then replying with bad info. Again I hope I helped, if you need anythign else ask.