Steam will usually offer different program options when launching Pinball Arcade, including Cabinet Mode. When starting from a shortcut, these options are not presented, instead launching directly into the default DX9 standard mode version of the program executable.
To change this behaviour and select Cabinet Mode as the default program executable, the full path to the Cabinet Mode executable can be entered in the Steam interface under Launch Options for Pinball Arcade.
Right click on Pinball Arcade from the list of games in your Steam Library, then click Properties. Click the button titled “Set Launch Options…” and enter the following:
“C:\Program Files(x86)\Steam\steamapps\common\PinballArcade\PinballArcadeCabinet.exe” %command%
Please note this is for the default install location. If your Steam program directory is located elsewhere on your system you will need to adjust the path accordingly.