> our $foo;

> is the same as

> alias my $foo = $MyModule::foo;

not exactly, it's never a variable from the lexical pad - aliased or not - it's only a lexically scoped package var. (i.e. a compile time effect)

~$ perl -MO=Terse -e 'package foo; our $x; package bar;print $x+$a'
LISTOP (0x820dd70) leave [1] 
    OP (0x820e2d8) enter 
    COP (0x820cc00) nextstate 
    UNOP (0x820dd90) null [15] 
        PADOP (0x820cb90) gvsv  GV (0x8208700) *foo::x 
    COP (0x820ddb0) nextstate 
    LISTOP (0x823e218) print 
        OP (0x8205710) pushmark 
        BINOP (0x820df38) add [5] 
            UNOP (0x820dd30) null [15] 
                PADOP (0x820dcf0) gvsv  GV (0x8208700) *foo::x 
            UNOP (0x820cbb0) null [15] 
                PADOP (0x82046c0) gvsv  GV (0x820869c) *bar::a 
-e syntax OK
[download]

but I have to admit that "lexical variable" has an ambiguity.

Though checking in perlglossary clearly defines

lexical variable

A "variable" subject to "lexical scoping", declared by my. Often just called a "lexical". (The our declaration declares a lexically scoped name for a global variable, which is not itself a lexical variable.)

update

OTOH is aliasing in Perl always a compile time effect, so your interpretation is not really wrong regarding the effect ...