Privacy
One upload, several near-copies left behind
Taking several frames to pick one leaves the others in your camera roll and cloud backup, where they persist after the chosen one is deleted.
Guides on Privacy: Who could see it, how, and what each path costs to close, Soft delete, backups, caches and logs, Sometimes, and the policy clause that says so is easy to miss
Yes - the burst frames you did not pick usually stay in your camera roll as separate files, and in the cloud if your library syncs. Taking five and keeping the best is a normal way to take a picture, but the four you rejected never went anywhere.
Why the rejects persist
A burst mode captures each frame as its own file the moment the shutter is held, before you have chosen anything. Selecting a favourite in the gallery app is a display action, not a deletion - the others remain unless you go back and remove them individually, which almost nobody does, because the whole point of a burst was not having to make that decision under pressure. Cloud sync compounds this: if the device backs up automatically, every frame typically uploads before you have picked one, so the rejects can exist in the cloud even if you later delete them from the device itself. What actually gets uploaded automatically, and when, is its own question worth understanding directly, covered in cloud photo sync and uploads.
Why deleting the one you sent does not help
If you upload one frame from a burst and later delete your account or your result, the frame you sent may well be gone from that service. The other four were never sent anywhere and were never subject to that deletion at all - they are a separate exposure, sitting in your own library, with no connection to any rating tool's retention policy. This is a different problem from what "deleted" means once a file reaches a server: that piece is about a service's copies, and this one is about copies that never left your own device and cloud account in the first place.
What to actually do
Periodically clear burst duplicates from your camera roll, the same way you would clear screenshots or downloads - most gallery apps group a burst together and offer a bulk "keep one, delete rest" action, worth using once you know it exists. If your library syncs automatically, check whether the cloud provider's trash or version history retains deleted items for a window after removal, since deleting on the device does not always mean deleted everywhere immediately. Google Photos' help page on deleting photos, for example, says deleted items "stay in your trash for 30 days before they are permanently deleted," and that deleting a backed-up item removes it "on all devices with backup turned on."
Where this sits relative to a photo you actually upload
None of it changes what a scoring model reads - only the one file you submit reaches the model, and the rejects never enter that path at all. It is purely a question of what sits in your own library, unconnected to any tool's handling of the file you sent. The same residue point applies to a still bundled with a short video clip, which is a related but separate way a phone leaves more behind a single shutter press than the shutter press implies. Choosing the best frame from a burst is also a comparison habit worth being deliberate about if you are tracking a submission over time - Penis Rater's notes on preparing a photo address that from the tracking side. A photo taken specifically for a human review has the same burst habit behind it, and what is worth sending on rather than leaving to sit - Rate Penis covers submission etiquette - is a related question from the recipient's side. None of this touches a measurement taken by hand, which Measure My Cock's method does not turn into a photo library entry at all, let alone a burst of them.