Currently, it loads the onscreen images when the scrolling stops (which is a non-aggressive loading behavior). If you wish to be more aggressive about loading the images, i.e. loads the images when the scrolling starts to decelerate, or loads the images as soon as the table scrolls (very aggressive), you can fine control the loading behavior via the loadInBackground method in PFImageView (the PFTableViewCell has a PFImageView as its imageView property).

In designing the API, I debated whether I should introduce a property that lets developer specify a loading behavior from a default set. I chose not to expose it for now and wait for some feedback; if this is a commonly asked feature, I can always introduce it later. I find, in the personal apps I build, this loading behavior is sufficient for 90% of them. Would love to hear others' feedback, though.