Appena sarai arrivata dal fioraio, mandami la foto del mazzo.

Because Italian is marking one future action as completed before another.

• sarai arrivata = future perfect
• mandami = command that should happen after that completed action

So the sentence literally works like:

• As soon as you will have arrived at the florist, send me the photo of the bouquet.

That sounds unnatural in English, because English usually says:

• As soon as you’ve arrived at the florist, send me the photo...
• or more naturally, As soon as you get to the florist, send me the photo...

Italian often uses the future perfect in this kind of time clause to show completion before the main action.

Because the past participle agrees with the subject when essere is used as the auxiliary.

Arrivare takes essere, so in compound tenses you get:

• sarai arrivato if speaking to a man
• sarai arrivata if speaking to a woman

So this sentence is addressed to a female you.

Because arrivare is one of the verbs that forms compound tenses with essere, not avere.

So:

• sei arrivata
• sarai arrivata
• not hai arrivata or avrai arrivata

Many verbs of movement or change of state use essere, and arrivare is a very common one.

Here appena means as soon as.

In other contexts, appena can also mean:

• just / only just: Sono appena arrivato = I’ve just arrived
• barely in some expressions

But in this sentence, with a clause following it, it means as soon as:

• Appena sarai arrivata... = As soon as you’ve arrived...

Because Italian often uses da with people and professions to mean to/at someone’s place.

So:

• vado dal medico = I’m going to the doctor’s
• vado dal panettiere = I’m going to the baker’s
• vado dal fioraio = I’m going to the florist’s

Here dal = da + il.

Using al fioraio would sound less natural in this context, because the idea is not just movement toward a place, but going to the florist / the florist’s shop.

Because in the informal affirmative imperative, object pronouns are attached to the end of the verb.

So:

• manda = send
• mi = to me
• mandami = send me

This is very common:

• dimmi = tell me
• scrivimi = write to me
• portami = bring me

If it were negative informal imperative, Italian often separates them:

• non mi mandare...

Because Italian usually leaves subject pronouns out when they are already clear from the verb form.

In this sentence:

• sarai arrivata clearly tells you the subject is you
• mandami is also an imperative addressed to you

So tu is unnecessary unless the speaker wants emphasis or contrast.

For example:

• Appena sarai arrivata dal fioraio, mandami la foto del mazzo.
• natural and normal

Adding tu would sound more emphatic:

• Appena tu sarai arrivata..., mandami...

Del is the contraction of di + il.

So:

• la foto del mazzo literally = the photo of the bouquet

This is a very common structure in Italian:

• il colore del fiore = the color of the flower
• la porta della casa = the door of the house
• il nome del negozio = the name of the shop

Here mazzo means bouquet or bunch, and in this context it clearly means a bouquet of flowers.

Yes, you could, and it would sound natural in everyday Italian.

The difference is mainly one of aspect and precision:

• Appena arrivi... = as soon as you arrive
• Appena sarai arrivata... = as soon as you have arrived / once you’ve arrived

The version with future perfect emphasizes the action being completed first. The version with the simple present can be more conversational and still refers to the future because of the time expression.

So both are possible, but sarai arrivata is a bit more explicit about sequence.

This is a common difference between the two languages.

In English, after words like when, as soon as, after, we usually avoid the future tense:

• As soon as you arrive, send me the photo.
• not usually As soon as you will arrive...

Italian is different. In future contexts, Italian can use:

• the future simple
• or the future perfect, especially when one future action happens before another

So Italian allows a structure that English learners may find surprising:

• Appena sarai arrivata..., mandami...

This is normal Italian, even though English expresses the same idea differently.

It is informal singular, used with tu.

So the sentence is being said to one person in an informal way.

If you wanted the formal Lei version, you would say:

• Appena sarà arrivata dal fioraio, mi mandi la foto del mazzo.

Notice the changes:

• sarai → sarà
• mandami → mi mandi

Yes, but the meaning shifts slightly.

• mandami la foto del mazzo suggests the photo you are expected to take
• mandami una foto del mazzo means send me a photo of the bouquet, with less focus on a specific expected picture

Italian often uses the definite article where English might sometimes use an indefinite one, especially when the context makes the thing identifiable.

Fioraio means florist. It is a noun referring to a person/profession.

It comes from fiore = flower.

In this sentence, dal fioraio means either:

• to the florist
• or more naturally, to the florist’s shop

So even though the noun refers to a person, the phrase can imply the business location too.