That is because Poser no longer deletes the images unless you tell it to.  The top where it says images path, that is where you will find the images that you create.  What you have showing is how to convert those images into a movie format if you want to.  In the past you would select a movie type and render and Poser would output all the images to a temp folder and when all images were finished it would then convert those images into the selected codex.  And if you wanted to make two different codex types then you would render those images twice or more depending.  Now you render them once and then select the type of codex you want to make, and it creates that type.  Then you can select another codex and convert those same images to the new format without having to re-render.  Space wise it takes up the same amount of room if you delete the frames afterwards.  In fact, if you really want it to perform like Poser 12 just check those 3 check boxes that are partly hidden by you pop-up. Then it will render the frames make a movie based on the option you select in the pop-up, play that movie and delete the frames.  You won't see any difference to Poser 12 if you do that.

The nice thing about the new way is that if for some reason the rendering is interrupted you can pick up from where it stopped and not have to re-render all the good frames again.  And if you have 500 frames and it gets to 497 and quits with the old method you get to redo those 497 frames again and spend that amount of lost time being updet.  The new method you just tell it to render frame 498-500 and then compile that codex.

Poser 5, 6, 7, 8, Poser Pro 9 (2012), 10 (2014), 11, 12, 13