It is very difficult to compare a visual window, on two different computers and environments. But, looking at mine from every option, my "large icon" view in windows 10, looks exactly like your 8.1 picture.
I wonder, have you been making any adjustments here:
That's still set at 100%, I did change the custom slider (located under advanced setting) to increase things to 120% but that was after I noticed the small control panel items and I don't think they got any bigger.
I'm actually having a lot more odd things happen with this build then I have the earlier ones.
Cortana sometimes talks and sometimes doesn't, Thunderbird keeps freezing unless I wait a while between actions.
And I noticed that all of my screen content seemed a little smaller than before but not as much as the Control Panel.