Are there any known limitations of Picture Library in respect to:
- Maximum number of items in the Library
- File size of individual files
- File types of individual files
I haven't seen anything published as such. The size and type would be limited by the web application blocked file types and the maximum upload size. The maximum number of files would echo the same principles of a large document libary, limit the number of items per view to avoid performance degradation and/or make use of folders.