Why? The dorsal pennant is found just below the lowermost lights there, and a comparable image from the opening credits shows what Riker would be seeing:
It's just us the audience that would be suffering from the lack of light and resolution, supposedly. A character from the show could spot the telltale suffix letter - which would be what they would be expecting anyway, what with two out of the supposed six Galaxy
class vessels having such a letter, and the idea of the heroes meeting themselves in the anomaly perhaps a less likely proposition than them meeting a sister ship.