Such plainness of the pre-baroque
Hardly involves the eye, until
It meets his left-hand gauntlet, still
Clasped empty in the other; and
One sees, with a sharp tender shock
His hand withdrawn, holding her hand.
They would not think to lie so long
Such faithfulnеss in effigy
Was just a detail friends would see:
A sculptor's sweet commissionеd grace
Thrown off in helping to prolong
The Latin names around the base.
They would not guess how early in
Their supine stationary voyage
The air would change to soundless damage,
Turn the old tenantry away;
The first lines of this and the previous stanzas are  syntactic parallels , with  anaphoric  repetition of “They would not …”. This adds emphasis to the negative aspects of the scenario that Larkin is exploring.
An Arundel Tombb