# Why is the morse potential shifted for two different electron energy levels?

I saw this image from the Wikipedia article on the Franck-Condon principle:

But couldn't find an explanation for the shift $$q_{01}$$ to the right (i.e. increasing the inter-nuclear distance) as the electron energy level goes from $$E_0$$ to $$E_1$$. As far as I understand it, the absorbed energy in an electron will push it to an outer-more electron shell, but is this the sole reason for the shift towards right in this graph? Is it simply, the further binding electrons are to the nucleus, the further apart the nuclei binds? And if so, does this trend continue for each subsequent energy level, $$E_2$$, $$E_3$$, etc. or are there other factors at play here?

As an example, when in a single-electron picture an electron is excited from a bonding orbital to an antibonding orbital, if there still is a minimum, it would be at a larger internuclear distance. Or when an electron is excited from a $$\sigma$$ orbital to a $$\pi$$ orbital.