Actually, it occurs to me that we shouldn't see all seven signals sent yet at all. The sixth and seventh signals don't originate from the same origin point as the first five, and Michael barely knows about the 7th until seconds before going through the wormhole itself. In theory, it would make more sense for her to send all the signals in an initial burst from the other side of the wormhole. What doesn't make sense is that the second and seven signals both originated from Terralysium (judging by the 51,000 light-years away comment), yet appear in different places on the maps of the signals that we are shown throughout the season.