This is not easy when there is wind/tide. It looked to me that the boat had to slow own (to avoid damage) to the point that it would lose forward momentum and slide right (from the POV of looking at the photo) and miss the trailer.

"Lake Lillinonah is located in...western Connecticut,...It is the second largest lake in Connecticut, smaller only than Candlewood Lake.[...The lake is bordered by six towns: Brookfield, Bridgewater, Newtown, New Milford, Roxbury, and Southbury.[2] It was formed in 1955 by impoundment of the Housatonic River and the Shepaug River by the Shepaug Dam which was built by the Connecticut Light and Power Company...
Max. length 12 to 14 miles (19 to 23 km)
Surface area 1,547 to 1,900 acres (626 to 769 ha)
Max. depth 110 feet (34 m)
Shore length1 45 miles (72 km)"
Wikipedia