Do I need to file a Nonresident Business Allocation Schedule to allocate New York State Income?

I am a self-employed and am a PA state resident. This year, two of my clients were from New York (I was signed on as an independent contractor for them) so I am filing a NYS tax return in addition to a PA tax return, but I am stuck on the question of whether I need to file a Nonresident Business Allocation Schedule to allocate New York State Income. 

 

I do not own or rent a desk/office space in New York, but have traveled to New York to conduct part of my services (photographer for live events) for these clients, while the rest of my services (editing photos/managing social media) were conducted remotely in PA for these same clients.