I think the small spider might have killed the larger one
and was feeding on it when I got this photo.

"Some species behave as kleptoparasites in that
they invade the web of a (usually larger) host
spider and eat the host’s web, glean insects off
the host’s web, steal the host’s wrapped food
bundles, and/or feed with the host. Some species
attack the host when it is vulnerable such
as during molting, or capture and eat small
spiders by lunging at them and grabbing them
with their front legs. Still others capture spiders
by throwing a line of sticky silk over the
victim."

This quote was taken from this site.