Hidden is the big difference between this "standing" and the "stood" in Luke 18:11 but you could never guess it from the translation. There are also a couple of unique words here for Jesus to use, one of which is highly symbolic. It also has a surprise mistranslation at the end that illustrates how Greek articles really work.

The Greek word translated as "and" means "but", "however", and "on the other hand". Since it always falls in the second position, translating it as "however" often captures its feeling better. 

The Greek term translated as "publican" means "farmer" and "tax collector." by Jesus's time, tax collectors were not tax-farmers, that is, private individuals who bought the right to collect taxes. Tax collectors worked directly for Rome, but the term "farmer" stuck from an earlier era when they were tax-farmers. Historically, these tax-collectors or rent collectors were notoriously corrupt, especially as tax farmers. They were made into government employees to reform them.

The verb translated as "standing" means "to make stand", "to set up", "to establish and similar words. The same word was was used in Luke 18:11. but it was passive, giving the double meaning of "upright" and "up close". Here the same word is active, as simple "stood".

"Afar off" is an uncommon adverb for Jesus to use that means "from afar" and "from long since". It may be a contrast to the previous verses sense of "up close".

The Greek word translated as "would" is not the same as the helper verb "will" in English, which primarily expresses the future tense. Its primary purpose is to express consent and even a delight in doing something. It means "to consent" and "to be resolved to a purpose". "Desire" usually works better.

The Greek word translated as "not" is the Greek negative used to deny objective facts, not opinions. It makes a negative statement of fact. Adding "really" to the sentence captures the same idea. Notice that, even though it refers to a desire, it is not an opinion because the Greek sense of "will" is stronger than our own.

"Lift up" is  a verb that means "lift up", "set on", and "raise". It also means "urge on," and "persuade", which adds flavor here. The sense his that he could persuade his eyes to look up.

The Greek word for "so much as" is an adverb that means "not at all" or "no even". It follows the "desire", accentuating the complete lack of desire not a lack of lifting. 

There is not "his" in the verse. This is substituted for an article which has the sense of "those". This adds drama to the story.

The Greek word for "eyes" is the more technical terms for "eye" but it also means "sight". It is a metaphor for "cheer." So looking down is the opposite of cheer. It has an article, so "those eyes" works. 

The word translated as "unto" means "into" a place, "towards" as a direction, "in regards to" a subject, and "up to" limits in time and measure.  These sense here is clearly "towards".

The word translated as "heaven" means sky, the climate, and the universe. It also meant the home of the gods in a physical sense: the sun, moon, and planets were named for the gods. More about the word in this article. It has an article, so "the sky".

The Greek word translated as "but" denotes an exception or simple opposition. It is used to emphasize the contrast between things like we use "rather". Here, "instead" works better. This is not the Greek word usually translated as "but" which began this sentence.

The verb translated as "smote" is from another uncommon word that means "to beat", "to strike," and "to smite." Christ uses a lot of different words to mean "to beat." This one seem reserved to punishment.

There is no Greek word "upon" here. 

"His" is a special reflexive pronoun that means "himself", "herself," and so on. It is more extreme that the normal word translated as "his" so, "his own".

"Breast" is a word that means "breast" (of both sexcs), but among the Greek, this was consider the seat of feelings and thought, specifically higher, nobler feelings. This is the same as thumos, ("chest") discussing this this article, 

The word translated as "saying" is the most common word that means "to say," and "to speak," but it also means "to teach,"

The word translated as "God" means "God" and "deity." It is introduced with an article, so "the God." Jesus often uses it this way perhaps to indicate the one God as opposed to the pagan gods.

"Be merciful" is a verb that Jesus only uses here that means "appease", and, in the passive used here, "to be merciful" and "gracious". This is NOT the "merciful" of Matthew 5:7 ("Blessed [are] the merciful")  or Luke 6:36 ("Be ye therefore merciful").

The "to me" is in the indirect object form on the first-person pronoun, so usually "to me", though the form has other uses in Greek. 

"A sinner" is an adjective that means "erroneous" or "erring."  Only in biblical translations is this term given the sense of wickedness. More about the translation issues regarding "sin" here.  However, the big issue is that is as an article so "the sinner" not "a sinner".  However, the Greek article is more like our "this" or "that" so the sense is "this sinner".   See this article for more.