[f5fstop]

Front drive pinion shaft seal is leaking and apparently leaking quite a bit.
As for driving, depends on how much has leaked out. You could pull the sight/fill plug and add some fluid, but the synthetic fluid is very expensive. Or using a coat hanger, pipe cleaner, etc. stick it in the hole and see how low the level is.

If it appears to leak only when rotating, that tells me the seal is either bad at the top, or if bad at the bottom, the level has dropped pretty low.