The wording does seem a bit odd - the head of the Department of Transportation "approves [a] request" from a city council member, as though the city council didn't have the ultimate power over the city's department of transportation. Rather than 'approving' it seems he should be "happy to carrying out the council member's request", or, if necessary, pointing out the regulation that is in the way. I know nothing about Selwyn Hollins*, but it seems a pompous way to respond.
I did google traffic signal box painting and got to The Power Of Art's website. I also found their business plan which included their mission statement:
"The Power of Art’s mission is to enable artists, organizations, and everyday people to paint murals on traffic signal boxes and in crosswalks on more than 4,000 street corners in Los Angeles. The vision of Power of Art is to unite and inspire Los Angeles’s artists, organizations, and everyday people by giving them the opportunity to leave their creative mark on history through artistically transforming their communities. "The art on the box above isn't quite my style - a little to Disneyish. I like this sort of stuff to be a little edgier, but a lot of people like this as well. And it's better than a plain box.
A mile later, when I got to the beach, I passed this selfie wall which gives people a place to take selfies with a bit of a smirk.
According to @The MostFamousArtist at #selfiewall, this was completed March 12.
*When I write something like "I know nothing about . . ." I, of course, then have to see what I can find. Here's a very brief bio.