[Plugin: Infinite Scroll] A faster response time

Hello,
We have recently had a developer code an infinite scroll for us. We like the way it works, but our clients get confused because it takes 5-10 seconds for the next page to load/the loading wheel to appear.

Is there a way to make the loading process experience more fluent or is there a way to have notification of page loading immediate?

We tried reducing the image size, but response is still the same.

Thank you!