Yes, exactly. To elaborate on Anonymous Monk’s answer:

12:41 >perl -Mstrict -wE "package myPackage; sub function1 { myPackage
+::function2('Hi!'); } sub function2 { say qq[@_]; } function1();"
Hi!

12:41 >perl -Mstrict -wE "package myPackage; sub function1 { function2
+('Hi!'); } sub function2 { say qq[@_]; } function1();"
Hi!

12:41 >perl -Mstrict -wE "package myPackage; sub function1 { myPackage
+->function2('Hi!'); } sub function2 { say qq[@_]; } function1();"
myPackage Hi!

12:41 >
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Within the package, prepending myPackage:: to a function name is merely redundant. But prepending myPackage-> changes the behaviour: it passes the package name to the function as the first argument.

Hope that helps,