In the second sentence, what difference does the way "On it" has been used make? Or is it just a matter of sentence choice?

Question

I came across a picture with a weird caption on facebook the other day.

I came across a picture with a weird caption on it on facebook the other day.

Are both the sentences grammatically correct?

Is there a difference in their meaning?

Or is it just a matter of sentence choice?

Answer 1

Consider:

A tablecloth with a wine stain...

A tablecloth with a wine stain on it...

In both sentences, with is understood to mean "having". As there are not many ways a tablecloth can be "with" a wine stain, "on it" is unnecessary; it simply reinforces the idea.

In the same way, a picture with a caption and a picture with a caption on it mean much the same thing, with the possible minor exception that someone might think "under" or "beneath" or "above" a more suitable preposition than "on", since captions usually do not appear directly "on" the picture. But "on" would be understood to mean "applied to it".