Thank you for the report!

This is an issue with Calendar, as they provide an image with a white background and quite some padding around the edges (which makes it look small).

We'll see some compatibility issues where sites include images specifically crafted for our message center that look different in the native toasts. We've got little other options than to sit through them and help sites out where possible.

I guess we are receiving the large calendar icon with good-sized padding and white background that we normally display in the old notifications system, and macOS is scaling it down to fit in the Mac notification icon area?

How exactly will Calendar transition to an icon that's better for us? If they start providing a more macOS-friendly icon, presumably that will make things look strange for users of the old notification system?

Is there a buganizer bug for this issue?

Yes, that's what's happening.

There is no great way to handle upgrades like this. From a compatibility point of view, our best option is to roll out to stable with a major release. That allows developers to switch based on the Chrome version.

I'll follow up tomorrow with a Buganizer link.

This is a problem for all properties indeed since it's not feature detectable, it would be even worse if we decide to Finch it on stable unless we go for a very tiny number.

We will be contacting all mayor properties we know of to mitigate this but there is really not much else we can do.

We'll follow up with the internal bug, so far it has just been an email conversation.