In January, people use a common expression every second. This means that in a new year every idea is new. This is the usual way people welcome the New Year with new features. For welcoming the year, fashion icons, celebrity or even just an ordinary person can do this “run up the flagpole and see if anyone salutes” because of their ideas for the first month of the year.
They want to make this year another new trend and stuff that people may say that it is the best idea in that type of trend in the new year to open up. “Run up the flagpole” is an expression that makes all the people notices your ideas. “See if anyone salutes” is also a term that someone may do what you do.