realtime mini-preview of minimized Window

does anyone know how to permanently get a live preview of a minimized window?

in detail:
when i minimize a window and then hover over it in the tray i can see a preview of the window and it's contents. sometimes this preview is updated in realtime sometimes not. - i havent figured out yet why sometimes it's not a reatime preview but the last "view" before minimizing.
what I am looking for is a permanent version of one of these previews.
I have a program which runs almost all day and does not need alot of attention.... I just need to "check on it" almost every five minutes to see if it still runs correctly and does its job the way it's supposed to. I am tired of constantly maximizing minimizing - instead i would like to have a mini preview of the window in which the program runs constantly open.... preferably alway on top.

any ideas? thank you : )

thanks, your reply just gave me the needed clue why sometimes i noticed the window updating in realtime and why sometimes not. It was my mistake..... the preview was only updating as long as the window was open at the same time - just as you said.

BUT.... i just had another idea. I just moved the open window to the right bottom corner of the screen... almost offscreen, where it doesn't get in the way. the minipreview of course just works the way it's expected.

now all i need is to find a way to keep the preview open all the time. preferably being able to move it around.
the better way would probably be an app which is made just for this particular need. infact this was actually what I was looking for in the first place. any application which displays the contents of another window in it's own SCALABLE window.

does anyone know a solution?
thanks ; )