When smilies are used within posts/threads that are part of Activity Summary emails, the smilie is displayed as bbcode instead of its corresponding image.
As per below screenshot, smilie is first and then an emoji. The latter displayed as an image, but not the smilie.
This is expected. Smilies aren't parsed in outgoing emails, including watched forums/threads and conversation emails going back to at least XF 2.0. The emoji is being rendered by your operating system font rather than an embedded image.
Smilies are not not parsed, and their respective image displayed, in emails. Instead we just get the bbcode equivalent, eg. "[:lol:]" The bbcode is meaningless and detracts from the email, making it look amateurish or faulty. With email alerts for watched forums/threads and conversations, and...