Show only the area needed to explain the issue. Crop away unrelated browser tabs and desktop windows, then check the remaining image for names, email addresses, account numbers, payment details, precise locations, private messages, access tokens, and QR codes.
For sensitive text, a solid opaque block is safer than a light blur, which may leave characters readable. Look again at thumbnails, reflections, notifications, and filenames; they are easy to miss. If you need to demonstrate an error, recreate it with test data when possible.
Finally, reopen the exported file you intend to upload. Some editors preserve an unredacted original or metadata, so do not assume the preview proves the shared file is safe.
Akousa