According to his experiments, recessive traits could be seen in a few members of the F2 generation. The probability of this happening is of about 25%.
I'll leave you an image, so you can see things more clearly. This is a brief explanation to understanding the images:
The capital letter such as "S" represent the dominant trait and the small letter such as "s" represent the recessive trait.
When you see an image with "Ss" it means that the dominant trait has applied. When you encounter and image with "ss" it means that the recessive trait has applied.
Hope it helped,
BioTeacher101