What you can do: manually extract the image URL via browser inspector. Any tool asking you to install something for this is likely malicious or useless.
While profile pictures are technically public, remember that VSCO is a community built on creative respect. Using someone’s image without permission—even if you’ve found a way to enlarge it—can violate the platform's ethos. Final Thoughts vsco profile picture viewer install
If you prefer a lightweight script (Tampermonkey/Violentmonkey): What you can do: manually extract the image
Because there is no "official" viewer to install, third-party developers have created tools to fill the gap. vsco profile picture viewer install