A sigle is a "magick spell" in the form of a visual gliph. A "meme" could even be considered a "sigle" They carry intention.
the witchcraft people charge them with intention, for specific goals.
I would say "Logo-s" for companies are often "Sigels" Or could be construed that way.
These images are called "Yantras" But the Sigel would be one a person creates privately; Similar idea. The "Chaos Magick" people might jack-off on the "mark" they create or do something to activate it.
Both "right hand" and "left hand" practitioners might use it.
"Sigel" could just mean "mark" or "sign"