It is a holographic laptop that allows her to infiltrate any info stored on any computer anywhere. It emits from the glasses themselves because if you remember, Storm, Emma Frost, and few other Xtreme Xmen all have a pair that they use for communication and they work just the same. so it's safe to assume that they dont come from her skin. also they have been shown to project images of blueprints, building schematics, ion trails, psionic residue,heat trails, discern the strengths and weaknesses of objects and people, and lastly, switch into different modes of the electromagnetic spectrum.(infared, x-ray, ultraviolet, etc.). Basically, these glasses are a giant data base that is able to cross reference info on any subject one could possibly imagine( I mean literally any subject). That, coupled with one of her innate mutant abilities to store and analyze data like a living computer puts her on equal footing with any "conventional" telepath when it comes to gathering information. Most importantly, she continually inputs new info on her "holo"laptop so her database can grow increasingly.Sage is listed as a cyberpath, which basically means she's a limited telepathic when it comes to pople, but with computers and all sorts of cybernetic technology she's basically like Prof. X
Sage is a cyberpath or a living computer brain. She is never doing what she is just doing. She multi-tasks like you would assume an ambidextrous person could do with their hands. She can't read minds but she can find avenues to attain different results to the same solution, making her more effective than an accident.