[raise] (some|a few|many|) eyebrows

to cause surprise, curiosity, or mild shock among people due to something unconventional, unexpected, or controversial

The idiom "raise eyebrows" is often used to imply that the action or statement is unconventional, unexpected, or unusual. The origin of this expression likely comes from the literal raising of one's eyebrows, which is a common physical reaction to surprise or curiosity.

Her irreverent chatter during the ceremony raised many people's eyebrows.
When she dyed her hair bright purple for her conservative office job, it certainly raised some eyebrows among her colleagues.
The decision to move to a remote cabin in the woods without electricity or running water raised a few eyebrows, but it was a dream come true for them.
What you just said may raise some eyebrows, but it shouldn't make anyone really angry.
His choice of wearing a tuxedo to the casual picnic raised eyebrows, but he wanted to make the day special.