Why my pdf is to big? Typst export WebP images to PNG

Hi. How did you check that images are converted to PNG?

When I open my pdf and save the images the final file is a png. But I think is a specs of my pdf reader.

Well I can reduce the size of pdf file with solution in this post

My problem now is the performance. I work with this command:

typs wacth file.typ

But the pdf is slow and big

Any suggestion?