This is one of the more tricky things to find, but if you are running Marshmellow, here are the instructions that seem to work. With Android, you do not get a hard drive that appears on your screen, nor does Photos work with Android, so try this instead:
- Plug in your Nexus 5X into your Mac
- Swipe down so you can see the type of USB transfer, unlike an iPhone, there are a bunch of options. If you want to transfer photos, then you need to select
transfer photos
and that start the Mac ApplicationImage Capture
which despite it’s name is actually going to copy off all the photos and videos. Hat tip to OS X Daily - If there are other actual files that you want, you need to download from the Google website the applications
Android File Transfer
and then make sure to select transfer file (because of course a photo is not a file?!!!). Then you will see the file system of phone and you can drag and drop into the Finder. I have had quite a few errors with this and the normal error is really confusing, it complains about the screen being locked. The most likely problem is actually that you didn’t select the proper “mode” for USB connections.