This is an intermittent problem. It will be difficult to diagnose.

Steps to reproduce (if it happens)

1. Run x URI-Ms through MementoEmbed (where x is unknown and may be a variable value)
2. Stop when you notice that the social card has not only an incorrect favicon for the archive but a favicon that belongs to a memento/original resource

Current Behavior

Sometimes a card includes a previous memento's favicon in the archive favicon position.

In the example below, instead of an Archive-It icon for the archive section of the card, there is an icon for slate.com:

Note how the above card's original resource is www.wikileaks.org, but the favicon chosen for the web archive is from slate.com. Once MementoEmbed chooses the wrong archive favicon, that choice appears on multiple future cards.

Expected behavior

The card should have the correct favicon for the archive and not a favicon from an original resource or memento.

For example: