A few sources are reporting a recent OTA to their Nexus with the build being FRF72. The previous beta release was FRF50. So it could be an update.
The changelog states that there are only minor changes to the browser and flash support. As with all rumors our good friends over at XDA-developers are skeptical since the photo could easily be faked. On the other hand a Google employee did tweet about getting an update.
Source: androidguys