How EasyBlog images "generator" work ?

Hi guys, i want to clear something out regarding EasyBlog image resize function. I just want to understand how things works.

1. In EasyBlog backend, under template settings we can define multiple image sizes.
Here we can define the width and height, define a "name" for the setting and setup a resize method ("resize to fill" , "resize within" , "resize fit")

2. In template file views, we output the desired size like this

<?php  echo $blog->getImage()->getSource( 'setting_name' ); ?>

So my question is:

1. EasyBlog will generate the sizes on "page view" ? When i access the page the "resize" mechanism is fired and generate the required size (the one "called" in the template view) for ALL the images outputed, right ?

2. Easyblog will generate the "resized" imaged for all images or only for the ones required based on the template "call".

What i mean by this is:

a) i have image A at size "thumb" and a different one, image B at size "large"
b) in template view i will output the "thumb" image resize setting for image A and "large" setting for image B
c) When the page is loaded (all easyblog image cache cleared of course). Easyblog will generate 2 sizes ("thumb" and "large") for both images ... or will generate only the required sizes for each one ? ("thumb" for image A and "large" for image B)

Hope you guys get what i am trying to say