This sign clearly does not mean what it says, and yet its meaning is clear. It is the nature of signs to employ succinct, nay even terse, wording. Utilization of space available.
If the gate were in fact kept closed and locked at all times there is an immense waste of posts, hinges, and locks, for all that would be needed is fence.
When I was a child we visited the grandparents in Southern California on occasion. For some reason I was taken with the "PedXing" signs. So much so that I found it fun to say. Repeatedly. And the parents found my saying it repeatedly to be quite annoying. At least I assume that is the case, as they told me to knock it off. (I still, on very rare occasions, and talking strictly to myself, find myself muttering a mantra which sounds a bit like "PedXing." I am not nuts.)
How easily I run off into uncharted territory. At any rate, back to signs. Some of these international signs elude me; but then, I don't "get" many of the icons on phones and computers. For instance, I would think that the circles would require a "/" through them if they mean "do not." E.g., I would think I could ride my bicycle down the path marked by the first sign in the second row. And who sponsors the last sign in the first row, "MaidenForm"?