There is no way to cancel "Find similar images"
Run "Find similar images" and the candidate images will be displayed in the CC Libraries Panel. If there is no image you want at that time, I want to cancel this. I want to delete candidate images in the CC Libraries Panel and return to My Library. However, there seems to be no other way than adding one of the images to the library or restarting InDesign.
The results of the Search for Similar Images can be cleared by clicking the ‘x’ button that appears next to at the top of the CC Libraries panel.
CS5 omachi commented
Oh, remove the CC library panel from the dock and close the panel. And you have to reset the workspace. What a tricky way! I did not notice at all.