Gemini 3 pro vs Gemini 3 Flash

The number of files processed by Gemini 3 Flash is greater than the number of files that can be processed by Gemini 3 Pro. How is this possible?

If I enter the same number of files into the template, Gemini 3 Pro tells me that the message is too long, while Gemini 3 Flash gives me the answer without any problems.