Join our CAD community forums where over 25,000 users interact to solve day to day problems and share ideas. We encourage you to visit, invite you to participate and look forward to your input and opinions. Acrobat 3D, AutoCAD, Catia, Inventor, IronCAD, Creo, Pro/ENGINEER, Solid Edge, SolidWorks, and others.
@4:03 he projects the rear edge into the sketch plane. I guess you projected the front edge which is shorter with the corner fillets. If you rotate the view, you can better see the rear and front edges.
These videos are made in perspective which (I think) does help see the part better. CATIA defaults to tri-axial views, which most people use. You can choose how the part is displayed with View + Render Style and choose parallel or perspective.