Not understanding 4k Timeline issue

I make a new project as 4k. Project settings show that it is. I drop a 4k clip in and it fills the window. I drop a 1080 clip in, thinking it will show up 1/4 the size of the window, but it also fills the window. ??? I don't get it. Why doesn't it come in at its actual size - 1/4 the size of the current project window? 

If you want the 1080 media at normal size, select the clips in the Browser, and in the Video inspector set spatial conform to None. It defaults to Fit.