yes - mouth blown only into the mould, with this concave-convex effect on the inner and outer surfaces, and the glass remaining the same thickness throughout.
The type of surface finish seen on the inside of the vessel can be a guide to the type of blowing or pressing that was used to inflate the glass, and these types of finish can be used to some extent as an approximate guide to age.
A completely smooth inside surface suggest either pressed with a plunger - so post c. 1840 (at least in the U.K.) - OR of course, free blown.
The other option is apparently where the plastic glass is is blown initially into a mould which imparts some pattern to the outer surface - then removed from the mould for further blowing - this apparently produces an irregular or part patterned inside surface, but not the true concave-convex effect mentioned above.
Fire polishing was used to remove the effects of mould seams.
Your comments about your bowl obviously mean it wasn't plunger pressed, so blown-moulded it must have been.
Tim Mills comments on this type of rummer bowl are very interesting, and he seems to be suggesting that this blown-moulded decoration was a cheaper alternative which was copying slice cutting.