BBC repository has a hard limit of its size. https://confluence.atlassian.com/bitbucket/what-kind-of-limits-do-you-have-on-repository-file-size-273877699.html
However, it's unclear if the total size of image files attached to Issue Tracker depends on the hard limit of its repository or has a dedicated limit.
Update the document to clarify if it depends on its repository's size limit or has a dedicated limit. https://confluence.atlassian.com/bitbucket/issue-trackers-221449750.html