Me neither, Neill.
Perhaps it rained, perhaps moisture, perhaps clouds. Let's see if we hear something from the Polarstern.
...
This photograph, i believe, was created from Polarstern's bridge ~3 days ago, 28th April:

Can you see the bear? Anyhow, from
the accompanying note posted at nasa.gov, we can read that the bear is, quote, "standing behind Met City near a small lead, likely waiting for a seal". Earlier in the note, we also read that bear, quote, "... sat near a small crack in the ice for almost two hours, likely waiting for a seal to surface". Seals, i understand, would need open water to come onto the ice, where polar bears could hunt them. So, it seems there are some areas of open water per the above - and it looks like at least some of such openings do not freeze up any much for ~2 hours. I don't think bears are that stupid to spend some hour+ hunting a piece of any significantly thick ice, are they?
Much more importantly, however, is shape of sea ice which above picture presents. As one can see, ice in this particular area is abundantly uneven. With Sun being low over horizon for the time being, this creates really long shadows, clearly visible on the picture. Yet surfaces which are _creating_ those shadows - are often nearly vertical, and thus they absorb lots of sunlight. I think those surfaces are wet, - now that air is much cleaner than in previous melt season, very long path it takes sun rays to go through the athmosphere (because Sun is so low yet) does not deplete energy of sunlight anywhere close as it did previous seasons. Like was mentioned couple pages ago, one can easily see from Finland shore all the way to Estonia now - visibility is _times_ better. Same story would mean times higher W/m2 hitting those "bumps" on sea ice, per above picture - and wet them up good deal even while overall 2m tempeatures may be at -10C or even lower.
And we clearly see the area was quite well lit as of 3 days ago, too.
If someone has any better explanation than above, then please share.