My last duchess by Robert browning

My Questions is - Whatr is the symbolic importance of the two pieces of artwork that the Duke shows the emissaary in the poem Q2. what are 3 qualities that make this poem a dramatic monologue? Q3. Identify and explain 3 of the duke's character traits that are revealed in the monologue Thanks for any help!

1That's my last Duchess painted on the wall,
2Looking as if she were alive. I call
3That piece a wonder, now: Frà Pandolf's hands
4Worked busily a day, and there she stands.
5Will 't please you sit and look at her? I said
6"Frà Pandolf" by design, for never read
7Strangers like you that pictured countenance,
8The depth and passion of its earnest glance,
9But to myself they turned (since none puts by
10The curtain I have drawn for you, but I)
11And seemed as they would ask me, if they durst,
12How such a glance came there; so, not the first
13Are you to turn and ask thus. Sir, 'twas not
14Her husband's presence only, called that spot
15Of joy into the Duchess' cheek: perhaps
16Frà Pandolf chanced to say, "Her mantle laps
17Over my Lady's wrist too much," or "Paint
18Must never hope to reproduce the faint
19Half-flush that dies along her throat"; such stuff
20Was courtesy, she thought, and cause enough
21For calling up that spot of joy. She had
22A heart . . . how shall I say? . . . too soon made glad,
23Too easily impressed; she liked whate'er
24She looked on, and her looks went everywhere.
25Sir, 'twas all one! My favour at her breast,
26The dropping of the daylight in the West,
27The bough of cherries some officious fool
28Broke in the orchard for her, the white mule
29She rode with round the terrace--all and each
30Would draw from her alike the approving speech,
31Or blush, at least. She thanked men,--good; but thanked
32Somehow . . . I know not how . . . as if she ranked
33My gift of a nine-hundred-years-old name
34With anybody's gift. Who'd stoop to blame
35This sort of trifling? Even had you skill
36In speech--(which I have not)--to make your will
37Quite clear to such an one, and say, "Just this
38Or that in you disgusts me; here you miss,
39Or there exceed the mark"--and if she let
40Herself be lessoned so, nor plainly set
41Her wits to yours, forsooth, and made excuse,
42--E'en then would be some stooping; and I chuse
43Never to stoop. Oh, sir, she smiled, no doubt,
44Whene'er I passed her; but who passed without
45Much the same smile? This grew; I gave commands;
46Then all smiles stopped together. There she stands
47As if alive. Will 't please you rise? We'll meet
48The company below, then. I repeat,
49The Count your Master's known munificence
50Is ample warrant that no just pretence
51Of mine for dowry will be disallowed;
52Though his fair daughter's self, as I avowed
53At starting, is my object. Nay, we'll go
54Together down, Sir! Notice Neptune, though,
55Taming a sea-horse, thought a rarity,
56Which Claus of Innsbruck cast in bronze for me