One effective method for discovering someone's name from a photo is to use a reverse image search tool like TinEye or PimEyes. These services allow you to upload an image or provide a URL, and they will then search the internet to find other instances where that image has been used. This can potentially reveal the name of the person in the photo if it has been published or shared online in connection with their identity.
Another useful approach is to try a facial recognition search engine like Google Images or Yandex Images. These tools have the capability to analyze the facial features in a photo and attempt to match it to other images online, which could lead you to the person's name if it is associated with those other instances. The key is to try a few different reverse image and facial recognition search options, as the results can vary depending on the specific service and the availability of information about the individual online.