The new Walt Disney Concert Hall is already a landmark in Los Angeles. And Frank Gehry's swooping, shimmering stainless steel building doubles as a frying pan. Sunlight reflected from its polished surface heats sidewalks to 140 degrees, causes sunburn to passersby and cooks neighboring condos. This week, the city's Board of Supervisors ordered Disney Hall to sand down the shiny parts. One admirer complained the directive would be like drawing the Mona Lisa's smile a little bigger.