This is Lio Tipton's second appearance on the show, having first appeared as herself in The Panty Piñata Polarization (2008) as one of the models from America's Top Models tracked down by Howard and Raj.
Part of this was shot on the Warner Bros lot, the lot is known for being used as the exterior scenes of Stars Hollow on Gilmore Girls. The restaurant where Amy and her date are eating was originally used as Doose's Market in the show.
Sheldon doubts the utility of online dating because he heard some sites use computer programs to simulate people. This episode aired the same year that the adultery dating site 'Ashley Madison' was shown to have set up 70,000 female bots to make male subscribers think a lot of desirable women used the site.
Penny alerting Leonard about making French Toast on "Oatmeal Day" is due to her having made the same mistake in Season 3 Episode 3, The Gothowitz Deviation (2009).
The turquoise t-shirt Sheldon is wearing when he meets the contest winner appears to display the Green Lantern oath, written in Interlac, the language used by the Legion of Super-Heroes.