Because Threads often compresses images, the native expansion might not show the highest possible quality. For a "true zoom" or full-size download, external tools are effective:
While most profiles allow expansion by default, users may occasionally have settings enabled—often synced from Instagram—that restrict profile picture expansion to protect privacy. If a profile picture won't expand, the user may have disabled in their privacy settings. Summary Table: Zooming Methods Threads DP Downloader - Full Size Profile Pictures threads profile picture zoom
Tools like Projoss are useful for creators who want to see how their own profile picture will look at various scales and crop levels before uploading. Privacy and Zoom Settings Because Threads often compresses images