Why in the manifest does it say by default “src”: “favicon.ico”, “sizes”: “192x192”, “type”: “image/png”. My hunch is that it’s a renamed PNG, indeed renaming to a PNG and it still opens and previews fine. All modern (and not so modern) browsers support PNGs too. Also it’s 64x64 but the manifest has it once as 192x192. I guess they thought 64x64 is enough and is a smaller file. Would have been good if they had explained their decisions.