Sure, here are 10 useful features for distinguishing an apartment building's outdoor area in a photo:

1. Building height and number of floors

2. Building façade, style, and architecture

3. Landscaping and greenery in the surrounding area

4. Presence of balconies, terraces, or rooftop decks

5. Types of windows (e.g. size, shape, material)

6. Presence of parking lots, garages, or driveways

7. Outdoor lighting fixtures and their placement

8. Street signs or other identifying landmarks in the background

9. Outdoor furniture or other amenities (e.g. pool, playground)

10. Condition and age of the building and its surroundings.