Realism has to indicate that it exists.
Speculation has to indicate that it will/may exist.

Realism indicates great possibilities of reaching reality.
Speculation indicates future possibilities/impossibilities with some plausible pathways.

Realism gives us aesthetics/functionality/lubrication.
Speculation gives us perspectives/preferences/unwillingness.

/// examples ///
"The Toaster Project" - Thomas Thwaites
"Silk Leaf" - Julian Melchiorri
"bGeigie Nano" - SAFECAST
"Mine Kafon" - Massoud Hassani
"PET Lamp" - Alvaro Catalán de Ocón
"Phonvert Project" - Phonvert

/// contact ///