First came the Soundlink, then a while later came the Soundlink Mini. So it was probably inevitable that Bose would follow up eventually with this new, micro-sized Bluetooth speaker.
It only makes sense, what with technology's continuous process of miniaturization and optimization. A computer that used to fill a room is now outclassed by a smart phone and room-filling speakers can now fill rooms from enclosures a fraction of the size of other types of loudspeaker.
With audio, however, the fly in the ointment is bass. Bass frequencies have longer wavelengths than the higher tones and that has traditionally meant you needed those honking big cabinets to reproduce those low frequencies faithfully, while you could get away with smaller speakers for the higher stuff. Hence the proliferation of subwoofers and satellite speakers.