The message on each side of the billboard switches from from "MAKE LOVE" and "SEND LOVE", to "MAKE CALLS WITH GLOVES ON" and "SEND TEXTS WITH GLOVES ON" when the temperature drops, as shown in the YouTube video below.
The promotional campaign was paired with Do The Green Thing's "Glove Love" initiative, a matchmaking service for single gloves. As a result Nokia created a "Glove Amesty" by giving away newly matched pairs of gloves in return for single ones. As Nokia explains:
The amnesty encourages Nokia fans to recycle single gloves to highlight how many gloves are lost as a result of taking them off to use a smartphone. To emphasise the activity, Nokia developed the first ever thermo-reactive billboard of its size which displays messages that highlight that the screens on Nokia Lumia devices are so sensitive you can even use them with your gloves on, so there’s no need to risk losing your gloves again.
The billboard was located at Westfield on 21st January and the Old Truman Brewery on 22nd January (both London). You might be wondering why Nokia only had the billboard up for two days. There's the obvious cost issue, but the real point of these promotional campaigns is to get some buzz on social media and to get the press to write about them, thus giving Nokia a free media buy (and, hey, it worked on us).