gasoline is a solvent, quite like paint thinner, what it does to the paint will depend on how much gas, how long it's on, what kind of paint it is, how old the paint is [cured], and whether there has been any wax applied - sometimes it doesn't do much, sometimes it takes off the wax before it evaporates, sometimes it stains the top coat, sometimes it dissolves the top coat, it has little or nothing to do with pre-paint prep
Michaels pic looks like it took off the top coat and left the [probably epoxy] primer - also, in some cases like Michaels [and mine], the gas expands over time and there's more of a 'flow' of gas rather than a drip .... bottom line, do not overfill your tank and take a chance

Bill