Can get an RSS feed by appending .rss to the URL:
https://mastodon.social/@flameReactor.rss
Then download that file and grep for:
https://files.mastodon.social/media_attachments/files/.*.png
Then download those PNG URLs.
That's how I assume/hope you implemented that. I guess, you could also download the whole Mastodon page and do the same grep, but yeah, RSS feed is going to be cleaner. 😅