are you sure you are picking a different sprite when you use the load action?
system: pick nth instance, (choose objecttype) and set instance number (could be var snapshotcount)
so if the snapshot objects already exist
add 1 to snapshotcount
other than that, its probably possible to use one instance, and first set frame and then load url
ps: you probably need to wait for loadurl is ready, but its thesame
onclick take snapshot
onready pick sprite, load url, add 1 to snapshotcount