In this scene we discover for the first time that Amy is definitively romantically predisposed to both lifeguards and Karma…
2x13 - Future Tense
Here we learn that Karma has had an established goal of wanting to become a summer lifeguard. Not sure when she developed this desire to seek out lifeguard as an occupation or whether or not it was spurred on by witnessing Amy’s whirlwind crush on that ‘mystery lifeguard’ alluded to in the diary entry that Shane skimmed.
2x20 - School’s Out
Following her tearful rejection of/by Amy in the 2B finale, Karma is seen arriving late for the first day of training as a pool lifeguard. While this may appear to be a seemingly innocuous coping mechanism, with Karma sticking to her back-up plan as a distraction for the crushing loneliness she was sure to endure without Amy around this summer… past evidence leads one to argue that Karma’s involvement as a summer lifeguard must be a subconscious attempt to win Amy’s affections upon her return next semester.
Combining her already notable charm and sway over Amy’s heart with that of Amy’s established Romantic predisposition towards water-safety workers, Karma’s insistence on moving forward & becoming a lifeguard (rather than relegating herself to a tearful, sobbing mess like she did following the rejection from the Season 1 finale…) is a deliberate move towards molding herself into a Mega-KarmaSexual Entity; attaining previously unmatched levels of irresistability, charm, and influence upon Amy’s return.