It is probably that these photos have been overwritten or damaged when new data written to the device. As soon as you realized that you've mistakenly deleted or lost important data, you'd better not do any operation to your iOS device. Any operation to your device such as taking photos, sending/receiving photos will overwrite your lost data and make them unrecoverable.
If your device is iPhone 4/3GS, iPad 1 and iPod touch 4, you can recover your photos with our product.
If your device is iPhone 11 Pro Max/11 Pro/11/X/8 Plus/8/7 Plus/7/SE/6s Plus/6s/6 Plus/6/5s/5c/5/4S, iPad Pro, iPad 4/3/2/Air, iPad mini/mini 2 and iPod touch 6/5, our product can support you recovering them as thumbnails from these devices.