Sure, here are 10 features that can help distinguish an alley in a photo:

1. Narrow or confined space: alleys are usually narrow and confined spaces between buildings, so look for the narrowness and enclosed feeling in the photo.

2. Tall buildings: alleys are often surrounded by tall buildings or walls, so look for the presence of tall structures in the photo.

3. Lack of sunlight: alleys are often shaded and don't receive direct sunlight, so look for the absence of bright sunlight in the photo.

4. Cobblestone or brick paving: alleys may have a distinctive cobblestone or brick paving, so look for this kind of texture in the photo.

5. Trash or debris: alleys are often used as dumping sites for trash and debris, so look for any litter or debris in the photo.

6. Graffiti or street art: alleys are sometimes used as canvases for graffiti or street art, so look for any colorful or artistic designs in the photo.

7. Fire escapes or ladders: alleys may have fire escapes or ladders attached to the buildings, so look for any metal structures in the photo.

8. Dark shadows and contrasts: alleys may exhibit strong contrasts between light and dark, so look for shadows and contrasts in the photo.

9. Minimalistic details: alleys often lack elaborate details, so look for a simple and utilitarian design in the photo.

10. People or animals: alleys may be used by people or animals as shortcuts or hiding places, so look for any signs of life in the photo.