Yes, alexan_e is right, but there are other methods:
Right click on it, go to "Edit properties", pick on "Edit all properties as text" then play (modify) the "{INVERT=1,2, ..." or "{INVERT=A,B, ..." line(s).
Make a simple circuit, which consists only the 7segment package, and switch in a segment using GND and Vcc to see what happens.
And what is the purpose of inverting the pins?
There are already available common cathode and common anode models for seven segment display.
What you describe only makes sense for the dot matrix display where only one type is available and you have to invert the pins in order to get an inverted model.
Was that checked?
The default is unchecked for components that have a footprint but it was checked in your case because you added your footprint in a component that didn't have one.
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By the way, please upload images in the forum instead of using external links.
After a while this links will not work and this thread will become useless.