I think that flowers and fences just seem to go together, like pie and ice cream. :) A neighborhood yard has some flowers that are quite pretty this time of year, including this one. I am guessing it is a type of Lily.

Yellow is said to be associated with optimism and pleasure. Maybe that is because sunny days are considered to feature yellow. A bright sunny day does lift the spirits and give a good feeling. Hopefully that is what this flower evokes.