In this picture, you have SDA connected to D1 and SCL to D2:
That seems to be reversed compared to this pinout diagram (from here), where SDA is D2 and SCL is D1:
I am not sure if that is the board you have, but I suggest checking to make sure you don’t have the I2C connections flipped.
(By the way, please upload pictures in a more common format like .jpg or .png if you can; that makes them easier to view on the forum.)
Also, is there any particular reason you are using Sparkfun’s library? We have tested our library with an ESP8266 board and confirmed that it works, and it looks like you’re already using our library with an Uno in your other thread.
Kevin