Few questions about playtest and GIMP

Hey there! im new to RPG Maker VX Ace and GIMP. But sometimes even the best tutorials cant explain simple issues i've been stuck on. 

I've notice on some videos that there is an option to resize the playtest screen (no resolution, size) and can actually see the whole game on the screen (no fullscreen), how do I do that ? (and please if its a script show me how and where to copy it as I said im new to this).

Something else i've noticed someone copied the playtest screen (or the lay, cant really say because he did it too fast) to the GIMP screen and started to add stuff and right after brought it back somehow to RPG maker with the new stuff from GIMP. I want to know mainly how do I copy the screen from RPG to GIMP ?

Btw, i've always wanted to make models on my own and i've been told gimp is the best. There are any recommanded special tutorial ?

Thanks alot!

When people make a video with just the game window shown that's normally part of their recording software that lets them only record that window/area of their screen.

As for the capturing the screen shots for Gimp use the "prt sc" (print screen) key on the keyboard (this makes an image copy of your screen on your clipboard) then paste it to gimp on a canvas that matches your screen resolution, then crop the image so only show the parts you want to show.

Thanks for help :) but what I've meant is when someone click on playtest he sees all the game in the playtest without fullscreen, is there a way to do that ?

and about copy the pic from RPG to GIMP, it is really works that way ? and possible to add anything I want ?

Oh you just want a non-fullscreen play test Up at the top click on the Game menu, you will see "Launch in Full Screen" just turn that off.