You can't put much stock in this photo being from philly just because someone anonymous says it is. And lots of those buildings of that era were cookie-cutter types (just like today) and looked very similar to each other, so you need to find another photo of that location from that time period to verify that location based on the total combination of visual elements. Or find another way to verify. In the news lately is a glass object that was sitting in a museum mislabeled, and only now discovered quite by happenstance to be a Picasso.
I find it hard to believe the location can't be pinpointed based on the plethora of information regarding philly buildings, esp considering 7th and Market is a pretty high profile location. And in my opinion some of the buildings in this particular photo seem too small for the Market street of that era, although the street scape is very much like your photo:
Market at 10th street looking East 1907:
Its also possible this may not be Philadelphia. Camden has a 7th and Market, and by one account had Philly Traction cars around this time. I can't seem to find many historical photos of Camden, but it was more prosperous then than now, and your photo kinda looks like a mini- Philly Market Street.