You have to realize that popular culture was very tightly controlled and restricted by the Polish communist government at this time. This photo was taken at the Jarocin festival, which was a rare chance to see many bands play that otherwise had no radio play or record contracts and often played styles of music that were viewed with great suspicion by the establishment. Recording these live performances and trading tapes was often the only way people got to hear many of these bands.
I grew up in a neighboring country during this time, but I wasn't much into the rock scene then - I was into folk music, which had a similar scene in my country - many folk artists were straight up banned by the government, so it was impossible to hear them on the radio or buy their records, but tape recordings of live performances existed and were traded among the fans. Same of my favorite music from this period only existed in this form. There were even recordings of shows that got shut down by the police mid-set.
The 80s were a period of economic stagnation in eastern Europe, resulting in a lot of pent up anger and angst in the youth, and at the same time, the establishment was slowly losing its grip on the population. As a result artists were getting increasingly bold in channeling this anger and dissatisfaction, of pushing the boundaries of what was allowed, sometimes crossing them and getting slapped down - but you never knew what could happen at a large gathering of the youth back then - taping was an important tool to document and spread this to the wider population.
Fast film (you can see how grainy it is when you zoom in a little) and shooting in full bright sun = you can shoot very short exposure and freeze motion. There were already cameras in the 1930s with mechanical shutters that could do 1/500th and even 1/1000th of a second exposure, which is plenty fast for this type of shot.
The lens looks pretty fast too - depth of field is very shallow, although part of that is also due to possible use of medium or large format - faster lens (lower f stop) and larger film both allow more light capture, and therefore faster exposure as well, but at the cost of less depth of field.