If you don't use pictures often, you can delete them by the following steps: 1. Open the file manager or photo album application. 2. Select the picture to delete, and then press and hold to select it. 3. Click the Delete or Trash icon. 4. Confirm the deletion operation. If you are not sure which pictures are not commonly used, you can follow these steps: 1. Open the file manager or photo album application. 2. Find the picture folder. 3. Click the "Sort by Time" option in the top menu bar. 4. Look at the pictures in chronological order and delete the early or unnecessary pictures. As for why so many unusual pictures suddenly appear, it may be because you recently used a camera or other applications, resulting in a large number of pictures saved in the album. It is suggested that when using the application, pay attention to the location and quantity of saved pictures, delete unnecessary pictures in time, and avoid occupying too much storage space.