A Transjovian wiki space managed by Phoebe is different from the Transjovian capsules managed by Phoebe.
The capsule is a single-person space where as a wiki can be a collaborative space, even if many wikis are effectively the work a very small number of people, possibly one.
The capsule needs no peer review, so no old revisions are kept beyond the limited backup files. There is no page history and no list of changes.
The capsule uses file name extensions to detect a limited number of MIME types (.gmi, .txt, .png, .jpg, .mp3) and treats everything else as a binary blob, where as the wiki saves the MIME type provided by clients on uploads doesn’t rely on naming conventions.
The capsule provides no feeds of any kind where as the wiki spaces have RSS and Atom feeds. Capsule authors can use the gemlog format, if they want feed-like behaviour.