When Lassie is crawling out of the river, the POV is from the river and the river is running from left to right. When she comes over the bank, the POV is toward the river, the water is running from left to right.
13 minutes into the film, Jock Gray placed the young pup Lassie on the ground, so she can learn from the Border Collie how to herd sheep. The view switches to the pup on the ground, but the pup on the ground is gray and doesn't have the same markings as the pup that Jock was holding.