Traianos Pakioufakis’s billboards caught my eye while I was passing on a bus: a flash of blue in my peripheral vision that had me turning to figure out what I’d just missed. They face a cycle path, beyond which lie a railway and a busy road, so stray glimpses must be all that many people ever get of them. Not in my case, though. I ventured back on foot for a closer look and was glad I did, the threat of passing cyclists notwithstanding.