You downloaded a retro indie game or an old port, but it is stuck in a tiny window. The config file mentions "720pfix." This usually refers to a workaround for software that cannot detect modern high-DPI displays or external GPUs.
Here is why old games need it:
Title: What is "720pfix"? Solving Low Resolution Lock & Scaling Issues Target Audience: PC gamers using old software or external GPUs (eGPU). 720pfix