iCloud photos don't show up in any editor I am new to MacOS (Sierra). I used iOS and iCloud photos for quite a long time now but I wonder why I cannot open any photo from iCloud photo stream in an editor like Pixlr to edit it directly. I know the workaround but I wanted to know if this is intended and maybe if there is a setting that I missed so far. 
I'd like to open photos from my photo stream directly in any editor and program.
Open up Pixlr, and when you go to 'open', in your sidebar you should have a Media / Photos option.  If you click that it'll show your albums etc.  See the screenshot...