Mendel thought that if two different characteristics, rather than just one are bred with each other. What do the progeny of a tall plant with round seeds and a short plant with wrinkled seeds look like? They are all tall and have round seeds. Tallness and round seeds are thus dominant traits, But what happens when these F1 progeny are used to generate F2 progeny by self pollination? A Mendelian experiment will find that some F2 progeny are tall plants with round seeds and some were short plants with wrinkled seeds. However there would also be some F2 progeny that showed new combinations. Some of them would be tall, but have wrinkled seeds, while others would be short, but have round seeds, you can see as to how new combinations of traits are formed in F2 offspring when factors controlling for seed shape and seed colour recombine to form zygote leading to form F2 offspring. Thus the tall/short trait and the round seed/wrinkled seed traits are independently inherited.
