Dolphin requested 128px thumbnail here. Wine executables have 32, 48, and 256 icons. It would pick the 48 one:
{F6132594}
Afterwards it would use the 256 ones
{F6132596}
The effect isn't neccessarily as noticeable with every icon and I hardly have any "real" windows EXE files around to test :)
Algo is basically copied from Plasma's wallpaper selection