The SLS head engineer plans to invite Shania Twain to stand under the completed prototype, then tell her, 'I don't expect you to date me just because I'm a rocket scientist, but you've gotta admit--this is pretty fucking impressive.'
SLS, which stands for Space Launch System, is the new launch program being designed by NASA to replace the retired Space Shuttle launch system. In the first frame, Cueball is showing Black Hat something about the SLS, possibly a video on his phone or other portable electronic device.
As usual with his appearances, Black Hat is causing trouble. Specifically he asks if Nazi scientists are going to build NASA's new SLS program. Specifically he mentions the former Nazi party member Wernher von Braun, who was one of the developers of the Saturn V launch vehicle, who came over to America (from Germany) as part of Operation Paperclip and helped develop NASA's space program. The unfortunate reality of Operation Paperclip, and one that Black Hat aims to make people uncomfortable with, is that a significant number of ex-German personnel were Nazi party true-believers, and their defection to America effectively granted them amnesty of any war crimes.
Black Hat extrapolates this sad reality into an obvious troll attempt: that putting actual Nazis in charge will get you results. This assumption is obviously a bridge too far (which is the comic's punchline), but he gets his desired reaction out of Cueball, who is hanging his head (or staring him down- Randall has left no details to distinguish). First he makes it clear that the lesson is that you should put the Nazis in charge (and we saw from World War Two what that could lead to). Then when Cueball states this is a terrible lesson, Black Hat puts salt in his wound by suggesting that the only way to find a better lesson is to ask a Nazi for a better one - a consistent move if you apply his lesson, but a logic bomb because he suggests to put a Nazi in charge of finding another lesson other than "put a Nazi in charge".
The title text is a reference to Shania Twain's song "That Don't Impress Me Much". Twain's lyrics include the line "Okay, so you're a rocket scientist / That don't impress me much". But, the title text argues that if she stood under the new SLS prototype, she would admit it was in fact, impressive. And it is thus the SLS head engineer (Garry Lyles) plans to invite Shania to do just that. Although he could still understand if she did not wish to date him, he would be surprised if she was still unimpressed.