Tjónþolinn sendir ljósmyndina.

Because Icelandic often puts the definite article onto the end of the noun instead of using a separate word.

• tjónþoli = injured party
• tjónþolinn = the injured party
• ljósmynd = photograph
• ljósmyndina = the photograph

So where English says the photograph, Icelandic can say ljósmyndina as one word.

The dictionary form is tjónþoli. It is a masculine noun, and -inn here shows that it is definite singular nominative:

• tjónþoli = an injured party
• tjónþolinn = the injured party

So the ending is doing the job that English usually does with the.

It is a noun here, not an adjective.

The base word is tjónþoli, which means a person who has suffered damage or loss. In this sentence, tjónþolinn is the subject: the person who is doing the sending.

Because ljósmyndina is the direct object of the verb sendir, and the verb að senda normally takes the accusative case.

For this feminine noun:

• ljósmyndin = the photograph, in the nominative case
• ljósmyndina = the photograph, in the accusative case

So:

• Ljósmyndin er ný. = The photograph is new.
• Hann sendir ljósmyndina. = He sends the photograph.

You know from both case and word order.

• tjónþolinn is the subject form here
• ljósmyndina is the object form

Also, this sentence uses the normal Icelandic statement pattern:

• subject + verb + object

So tjónþolinn is the one doing the sending, and ljósmyndina is the thing being sent.

Sendir is the present tense form of að senda.

In this sentence it is third-person singular because the subject is tjónþolinn.

A few present-tense forms are:

• ég sendi = I send
• þú sendir = you send
• hann/hún/það sendir = he/she/it sends

So here sendir means sends.

Yes. Icelandic present tense often covers both meanings that English separates into:

• sends
• is sending

So Tjónþolinn sendir ljósmyndina could mean either one, depending on context.

It is a fairly formal word, often used in legal, insurance, or administrative contexts.

It means a person who has suffered damage, loss, or injury. Depending on context, English translations might include:

• injured party
• claimant
• victim
• the person who suffered the loss

So it is not one of the most everyday words in Icelandic.

Because ljósmynd specifically means photograph.

The word mynd is broader and can mean things like:

• picture
• image
• illustration
• film/movie, in some contexts

So ljósmyndina is more precise if the thing being sent is an actual photo.

Yes, but Tjónþolinn sendir ljósmyndina is the most neutral way to say it.

Icelandic word order is more flexible than English because case endings help show what each word is doing. You can move things for emphasis, but in a main clause the finite verb usually stays in second position.

For example:

• Tjónþolinn sendir ljósmyndina. = neutral
• Ljósmyndina sendir tjónþolinn. = marked emphasis on ljósmyndina

So the sentence you have is the straightforward, unmarked version.

Þ is pronounced like th in thing.

It is not like th in this.

So in tjónþolinn, that letter has the unvoiced th sound.