The artist calls these "sloppy," but I call them loose and lively and gestural. Warm ups are important before doing your "real" drawing. It's kind of like being a relief pitcher. You don't just step onto the mound and go to pitching. You warm up in the bullpen first, then take a few throws from the mound. Artists have to do something similar to loosen up and start making lines that flow properly. These drawings are what those warm ups look like. Most of the time we don't share them, but sometimes the warm ups themselves are kind of interesting and useful and worth looking at. Like these.
That's a free art tip!