It's a creamy garlic, oil, salt, and lemon juice emulsion like Provençal aioli. Modern aioli recipes often use egg yolks or mayonnaise, but toum does not.
Trader Joe's dips have varied reviews, but this one is good. The Trader Joe's Garlic Dip-Spread reminded me of my first Lebanese takeaway toum in college. The food is great, but not for a first date.