Signing a unilaterally-written document is not "mutual", no matter how the other party wants to label it. Sure, the text inside says "we won't divulge each other's IP", but that's only one part of the agreement. Are the penalties equal? Are you forfeiting venue or agreeing to arbitration in a default?
If you do sign it without legal review, that's just foolish.
There are two senses of the term "mutual" being conflated here.
Grandparent is correct that as a term of art, a "mutual" NDA is one that puts non-disclosure obligations onto both parties.
Parent is perhaps usefully pointing out that the agreement is likely not "mutual," meaning entirely symmetric and evenly weighted between the parties. A fair argument, but confusing to folks who are working out NDA terminology 101.
Still, though, you'd call it a "mutual" NDA to distinguish it from a one-way NDA.
If you do sign it without legal review, that's just foolish.