Is it possible to pin a topic as an alias?

Wondering if it is possible to pin a topic as an alias, such as “system”. Currently, however pins the topic is displayed as most recent activity to that topic.

Thanks for any advice!

No, the avatar of the user who pinned the topic cannot be changed from the UI but you could change it via the console since you have a .json file with all the data you need, e.g.

id	5837
post_number	39
post_type	3
action_code	"pinned_globally.enabled"

or you can simply impersonate system with a developer account to pin the topic.