Not sure I understand the 'Opposites' in this shot. Compositionally, the sign's shadow on the grass and the inclusion of part of the building on the extreme right are both distracting, I think the composition would be better without them.

I haven't been able to figure out the "opposites" aspect of this. There's lots of detail in those shadowy areas though and the contrast with the sign makes it very prominent.

Subtle, but I like subtle!

Probably it's me but I don't get it... and as a photo it doesn't say much to me.

Now that's a sign you don't see around hospitals much anymore.