plugin does nothing!?

i tried smush.it now, well it works…somehow. I would like use this one instead because its new ?? A problem with all this plugins (working an not-working) is the image size of additional thumbnails.

i use sizes like 75×75 – have a look at this:
https://www.toureal.de/wp-content/uploads/2013/01/usa-mietwagen-004-75×75.jpg

insane 25kb and even smush.it can’t reduce it.