Google saying I need to optimize images even though I've optimized

Dear Smushers
I spent a lot of time today smushing images, I just ran the bulk smush. The reason I opted for this kind of programme was because I ran googles speed test on my site and it said that I really needed to optimize my images. I was really excited today once the smushing had finished, to go and run that test again, however my score didn't change much and it's still telling me to optimize images. (please see attached screenshot) I'm not quite sure what to do now as they are optimized, when I go into my media files it says this has been done.

Do you have any advice? Have I done something wrong?
I really appreciate any time that you can give me.
Thank you

Kind regards
Chantal