Luffy’s body-language claims a five-person crew when only three are visible. Nami (recovering offscreen) plausibly accounts for one finger. The second finger is deliberately ambiguous — Sanji (next to him at the bar) is the textual read; the chapter is playing both reads simultaneously.
Predictive use: the finger-count-exceeds-visible-crew gesture is a recurring Luffy-tell for who’s about to join. Watch for this gesture in pre-recruitment chapters of every Straw Hat. The gesture encodes the recruitment-prediction in the body before the recruit has agreed (cf. Luffy’s recruitment-instinct firing for Zoro Ch. 2, Usopp Ch. 41).