When you create an empty folder on macOS Catalina (10.15.4) via Finder (Right Click > New Folder), and check its information (Right Click > Get Info), the "Size" attribute shows:
Zero bytes (Zero bytes on disk) for 0 items
However, if you create an empty folder via Terminal (mkdir folder), and check its information the same way, the "Size" attribute now shows:
Zero bytes (Zero bytes on disk) for 1 item
There doesn't seem to be anything hidden in the folder created from CLI.
Why is there such a difference ("0 items" vs. "1 item")?
For those who're interested, below is the ls -al output.
emreerokyar@MBP gui_vs_cli % ls -al
total 0
drwxr-xr-x@ 4 emreerokyar staff 128 May 7 22:32 .
drwx------@ 5 emreerokyar staff 160 May 7 22:32 ..
drwxr-xr-x@ 2 emreerokyar staff 64 May 7 22:32 cli
drwxr-xr-x@ 2 emreerokyar staff 64 May 7 22:32 gui
emreerokyar@MBP gui_vs_cli % cd gui
emreerokyar@MBP gui % ls -al
total 0
drwxr-xr-x@ 2 emreerokyar staff 64 May 7 22:32 .
drwxr-xr-x@ 4 emreerokyar staff 128 May 7 22:32 ..
emreerokyar@MBP gui % cd ..
emreerokyar@MBP gui_vs_cli % cd cli
emreerokyar@MBP cli % ls -al
total 0
drwxr-xr-x@ 2 emreerokyar staff 64 May 7 22:32 .
drwxr-xr-x@ 4 emreerokyar staff 128 May 7 22:32 ..
emreerokyar@MBP cli %
Below are some screen shots.
Best Answer
It appears that it was a bug in macOS Catalina (10.15.4), which is now fixed on macOS Big Sur (11.0.1). So the outputs are consistent now - both are showing: