Fixing Broken Images in Mixpanel Slack Link Unfurling

when using the mixpanel extension in slack that unfurls links, for some reason, old messages get a broken image after some time, making it pretty annoying to scroll through old threads where these links are posted (see screenshot); can the extension be changed so that it attaches an actual image that doesn't expire to the slack message (as opposed to an embed that breaks after a few weeks)?