It's just a really bad parking lot design.
Regardless, Smart Summon doesn't currently care about things like directionality in a parking lot. This version doesn't try to do anything fancy like reading markings on the pavement.
The app will show you on a satellite map the route that the car is planning to go, assuming this release follows what was shown in the early access releases.
As the person supervising its behavior, it's currently solely your responsibility to make sure that the car doesn't cause problems for other people. The car will do its best to avoid hitting anyone or anything while still making it to your location, but you're still the one in charge.
Smart summon currently works via a dead man's switch. You have to hold down a button the entire time, and if you let go of the button for any reason, the car immediately stops.
The long-term goal is that supervision won't always be necessary, of course, but this feature is available now -- with supervision. If you see an opportunity to use it, it's there. It will get better. I've personally watched Autopilot grow up from something barely usable as a driver assistance technology to something that works extremely well for every day usage.