‘Sankhara paccaya vinnana’ is not the same as ‘upadana paccaya bhava.’
What happens is that in the “tanha paccaya upadana” step, one gets “trapped” in that particular arammana, in your example, an attractive woman.
– Then one would start generating lustful thoughts (vaci sankhara) about the woman and may turn and take another look (involving kaya sankhara.)
– Those sankhara are generated due to avijja via “avijja paccaya sankhara.” Then it creates or feeds the “lustful vinnana” via “sankhara paccaya vinnana.” That then goes through the rest of the PS steps including revisiting the “tanha paccaya upadana” step. The next step there is “upadana paccaya bhava” and thus he is in a “temporary lustful bhava.” Then he may be “born” in that lustful state and may take further actions, such as going and talking to her.
– Paticca Samuppada steps are not necessarily linear as I discussed in the past few posts.