Si nos sentamos en una fila más alta, veremos mejor las caras de las actrices en cada escena.

This is the normal pattern for a real or likely future condition in Spanish:

• Si + present tense, then
• future tense (or sometimes present/imperative in the other clause)

So:

• Si nos sentamos en una fila más alta, veremos mejor...

means If we sit in a higher row, we’ll see better...

Spanish does not normally use the future tense right after si in this kind of sentence. So Si nos sentaremos... would be incorrect here.

A similar example:

• Si llegamos pronto, encontraremos buenos asientos.
• If we arrive early, we’ll find good seats.

Because sentarse is a reflexive verb, meaning to sit down / to seat oneself.

• me siento = I sit down
• te sientas = you sit down
• nos sentamos = we sit down

So nos means ourselves here.

Compare:

• sentar = to seat someone / to place someone in a seat
• sentarse = to sit down

Examples:

• La acomodadora nos sienta en la primera fila. = The usher seats us in the front row.
• Nos sentamos en la primera fila. = We sit down in the front row.

Good question. Sentarse is a stem-changing verb (e → ie), but that change does not happen in nosotros and vosotros forms in the present tense.

So:

• me siento
• te sientas
• se sienta
• nos sentamos
• os sentáis
• se sientan

That is why the sentence uses nos sentamos, not nos sientamos.

Here, fila means row (for example, in a theatre or cinema), and alta means higher.

So:

• una fila alta = a high row / a row farther up
• una fila más alta = a higher row

Spanish often uses alto / bajo for physical position. In a theatre, a higher row means one farther up the seating area.

You could think of it as:

• en una fila más alta = in a row that is higher up

Because the sentence is comparing the physical position of the row, not saying the row is better in a general sense.

• más alta = higher
• mejor = better
• superior = superior / higher, but often sounds more formal or abstract

In everyday Spanish, una fila más alta is the natural way to say a higher row in this context.

In Spanish, ver and mirar are related but not identical:

• ver = to see
• mirar = to look (at)

Here the idea is about visibility and how well you can see the actresses’ faces, so ver is the right verb.

• Veremos mejor las caras... = We’ll see the faces better.
• Miraremos las caras... would mean We’ll look at the faces, which is a different idea.

So ver mejor is natural because it focuses on the quality of what you can see.

Because mejor is acting like an adverb here: it modifies the verb veremos.

• ver mejor = to see better

So:

• veremos mejor las caras = we will see the faces better

This is the normal word order in Spanish.

Because the sentence specifically means the actresses’ faces, not just the actresses in general.

• veremos mejor las actrices would sound wrong here
• veremos mejor a las actrices would mean we’ll see the actresses better
• veremos mejor las caras de las actrices means we’ll see the actresses’ faces better

Spanish often uses de to show possession:

• la cara de la actriz = the actress’s face
• las caras de las actrices = the actresses’ faces

Because las actrices is not the direct object of the verb. The direct object is las caras.

Structure:

• veremos = we will see
• las caras = the thing we will see
• de las actrices = of the actresses

So las actrices is inside a de-phrase, not the main object.

Compare:

• Veremos a las actrices. = We’ll see the actresses.
• Veremos las caras de las actrices. = We’ll see the actresses’ faces.

The personal a is used before specific people when they are the direct object, but here they are not.

Both are possible, but they mean slightly different things.

• en cada escena = in each scene
• en todas las escenas = in all the scenes

In many contexts they are very close in meaning. Cada emphasizes the scenes one by one, while todas las emphasizes the whole set.

So en cada escena is perfectly natural and means that in every individual scene, the faces will be easier to see.

Because cada is followed by a singular noun in Spanish.

So:

• cada escena = each scene
• cada actriz = each actress
• cada fila = each row

This is different from English, where learners sometimes expect a plural idea because the meaning refers to many items. But after cada, Spanish uses the singular form.

Yes, but that would change the meaning.

• Si nos sentamos..., veremos... = If we sit..., we’ll see...
  This sounds real and possible.

• Si nos sentáramos..., veríamos... = If we sat..., we’d see...
  This sounds more hypothetical, less direct, or more like a suggestion.

So the original sentence presents a realistic future possibility, which is why the present + future pattern is used.

Yes.

• actriz = actress
• actrices = actresses

This is a common noun pattern in Spanish:

• nouns ending in -z usually change the z to c before adding -es

Examples:

• luz → luces
• voz → voces
• actriz → actrices

Yes, this is a natural and correct sentence in Peninsular Spanish.

It sounds like something someone might say in a theatre or performance setting when talking about where to sit for a better view.

Very natural parts include:

• Si nos sentamos...
• en una fila más alta
• veremos mejor
• las caras de las actrices
• en cada escena

So for a learner, this is a good example of everyday, idiomatic Spanish.