From the Hubble site.

Here's Phil Plait's explanation:

Wow! You can see yellowish volcanic Io in the upper right, Europa on the lower left, and Callisto to its upper right. You can see two moon shadows, too: Europa’s to its upper right, and Callisto’s way over on the upper right on Jupiter.

It took me a second to wrap my head around the geometry: Why is Europa’s shadow close to the moon, but Callisto’s is so far off? That’s because Europa orbits Jupiter much closer in than Callisto, so the shadow it casts doesn’t fall as far away. Io casts a shadow too, but it’s off to the right, and misses Jupiter, so we don’t see it.

Here's Phil's entire post on these transits (N.B., not technically an eclipse):
http://www.slate.com/blogs/bad_astronomy/2015/02/07/jupiter_pentuple_transit_five_moons_move_across_the_planet.html