All I can see here is...like, hair, and maybe some random aggregates?
What are we supposed to be looking at? There are no obvious cultured cells here (which, you know, is quite important), and given the images, the magnification isn't sufficient to even make a guess at bacterial contamination, even if there was anything TO contaminate.
Bacterial contamination tends to appear by the turbidity of media. In most cases, we confirm mycoplasma contamination by PCR methods. Your images are confirming that there were no cells in the dish.
These are fibers, possible cotton from plugged pipettes. If you had bacteria, you would know i. Wwithin a few days the media would be overgrown with microorganisms so dense that it appears cloudy.