Gatekeeping waste of time. It looks like their previous developer left in February and they've been trying to keep everyone out.
The guy shared a bunch of snippets of code that were about 500 lines each and asks what you'd add, and he gives you about 3 minutes. This is designed to fail all of the candidates.
Typical clueless company where the only developer left is trying to keep everyone else out. He just waits for your answer and fails you and you can't answer because he's silent. There's no conversation here because the "answer" is secret.