Ask HN: Why is the Twitter logo a Shiba Inu?

I noticed my Twitter bird icon has replaced by a Shiba Inu. Clearly I'm not the only one, e.g.: https://twitter.com/search?q=shiba%20logo&src=typed_query

Here's an example of someone else commenting on it: https://twitter.com/HallowWolf2/status/1642943643479687182

Any idea what's going on here?