The 'Berlei controllette [corset] no. 6181 SBW (short below waist) type'. The design is particularly beautiful and has echoes of art deco in the triangular shapes and filigree font.
The woman depicted has a look of control, poise and dignity despite appearing in her underwear with the addition of a shawl, necklace and earrings. Her hairstyle is typical of the shorter cuts popularised by the flappers of the 1920s.
In 1926 Berlei and physiologists from the University of Sydney did an anthropometric survey of 6000 Australian women (of European descent) in order to find different figure types. The types they created were Sway Back Type, Hip Type, Abdomen Type, Average Type and Short Below Waist Type. Having many women fit into these categories meant they could manufacture corsets ahead of time and simply supply the correct size for the customer's measurements.
This slide would have been used as part of the training for prospective Berlei corsetieres.