OK this is funny. If you have a folder in your pasteboard and hit paste on Mastonaut’s composer, it actually fetches the folder icon from the pasteboard and uploads it as an attachment. I have no idea how to prevent this from happening. Example:
This Mastodon instance is for people interested in technology. Discussions aren't limited to technology, because tech folks shouldn't be limited to technology either! We adhere to an adapted version of the TootCat Code of Conduct and follow the Toot Café list of blocked instances. Ash is the admin and is supported by Fuzzface, Brian!, and Daniel Glus as moderators. Hosting costs are largely covered by our generous supporters on Patreon – thanks for all the help!