xargs prompts with the same string, but executes differently

[積丹尼 Dan Jacobson]

Proof that xargs prompts with the same string, but executes differently:

$ echo 0 0 | xargs -p -I{} xdotool mousemove {} click 1 mousemove restore
xdotool mousemove 0 0 click 1 mousemove restore ?...y
xdotool: Unknown command: 1
Run 'xdotool help' if you want a command list
$ echo | xargs -p xdotool mousemove 0 0 click 1 mousemove restore
xdotool mousemove 0 0 click 1 mousemove restore ?...y
$ xargs --version
xargs (GNU findutils) 4.6.0.235-f254 ...