The message can include keywords for symbols. In some Siemens telephones is keyword displayed like corresponding picture. With C35i you can choose from 25 pictures:

In C35i firmware exists 12 next pictures morover mostly including corresponding keywords!

Bomb Champagne Emergency Success HappyStarr
Winner Reply SuitCase Theatre (!) Attention
? ?

But sorry, any hidden keyword is not displayed like picture. This artefact gallery is archeologic curiosity only.

Programmer's joke

Theatre? Cinema!    This picture is Cinema self-evidently, but is used under ill-fated number with inadequate keyword.
Keyword "%Theatre" is suitable for one of hidden pictures.