New images (and other files?) can be attached to a notebook simply by pasting their contents. However, when selecting the “Replace file” context option of an attached file, the following dialog only allows dragging or uploading of a replacement file.
I’d love to see an option to paste the replacement. Additionally, if the MIME type of the pasted content no longer matches the file extension, and if a default file extension for the new MIME type is known, replace the file extension, but keep the basename intact.
Unrelated to the above suggestion, I’d also like to suggest the addition of an option to edit the current and/or new file name.