It seems that the real problem is not actually reading the OP question, however good the advice is. MM gets the prize for being first with the answer.
In my humble opinion, the three drone cells look a bit odd. In fact they look to be drone cells in a bit of worker comb. The cappings beingf muffin shaped, domed higher than regular drone brood.
If you are currently treating with Apiguard or have a new queen then it may be a bit of a misfire or the bees could have moved a couple (three actually) eggs.
Keep an eye open. It's probably nothing to get excited about unless you start to get a lot more lite them. It could of course be that my eyesight isn't what it was, but I don't believe that to be the case.
The part below the first bar of course didn't have foundation in and the bees built it themselves. Occasionally I have standard national brood frames in amongst 14x12 and they build brace comb down to the depth of the surrounding 14x12 frames. It is built as worker, drone or a combination of both, depending on what they feel a need for. In your photograph, there are undoubtedly drone cells, but where the three cells are looks to be worker sized cells. Don't worry, but nice observation and very sensible to seek advice.