This is what's called a VBR or variable bitrate file. What's great about VBR is that you can have frequencies above and below the bitrate median. First, let me point out the three visible lines here at 12khz, 16khz, and just below 20khz. The most profound line is at 16 with some highs going above which makes the median a 192khz mp3. This looks to me like a higher-quality file than what it says. Second, It may have been recorded using a tape or vinyl and those high frequencies could be noise considering the exact intervals between each line (vinyl/tape spinning).
Hope this helps!