When Ronnie was finished reading the fax, did he have second-thoughts about rejecting Giles? I mean, he was about the trash it until he found the script near the end. Then we see that it was filmed for HPC3. Then the film ends w/ a handshake (assuming Ronnie & Giles).
shareThe handshake was a flashback of Giles and Ronnie's initial meeting on the beach. Giles had offered Ronnie a chance to further his career in Europe, away from the shallowness of Hollywood.
The fax that followed evidently made an impression on Ronnie, as Giles poured out his thoughts and feelings, anticipating the regret Ronnie would eventually feel of wasted opportunity, wondering what could have been. We know that Ronnie was sick of playing "dumb kids". The quote by Walt Whitman seemed to Ronnie like a chance to get his career out of a rut, to show that he had the potential to be an actor of substance, something more than a B-grade teen heart-throb.
It's possible that the final frame of the handshake could symbolise Ronnie's acceptance of Giles's wisdom. Perhaps Ronnie did go onto better things than the "Hotpants College" sequels. I don't think it was meant to indicate that Ronnie decided he was romantically attracted to Giles after all.