General Synonyms:
* Images
* Photographs (if referring specifically to photos)
* Illustrations (if referring to drawings or sketches)
* Paintings (if referring to artwork)
* Visuals
* Graphics
* Depictions
* Representations
* Portrayals
More specific synonyms:
* Snaps (for informal photos)
* Shots (for photos taken with a camera)
* Prints (for physical copies of photos)
* Sketches (for simple drawings)
* Drawings (for more detailed illustrations)
* Paintings (for artwork created with paint)
* Cartoons (for humorous drawings)
* Posters (for large printed images)
Other synonyms:
* Views
* Scenes
* Visions
* Appearances
The best synonym for "pictures" will depend on the specific context and meaning you want to convey.