Jo també somric quan veig fotos de la meva mare i de la meva germana.

Yes. Somric already tells you the subject is I, so jo is not strictly necessary.

Catalan often drops subject pronouns, so També somric quan veig... is perfectly natural. Adding jo gives a bit of emphasis, contrast, or clarity, as if saying I also smile.

També means also, too, or as well.

In this sentence, it comes before the verb phrase, so it means I also smile. That is the most neutral placement here.

You may also hear Jo somric també, but that often feels more like I smile too / as well, with slightly different emphasis.

Because the infinitive is somriure and its present-tense forms are irregular.

The present tense is:

• jo somric
• tu somrius
• ell/ella somriu
• nosaltres somriem
• vosaltres somrieu
• ells/elles somriuen

So somric is simply the correct I form of somriure.

That is another irregular verb.

The infinitive is veure and the present tense goes:

• jo veig
• tu veus
• ell/ella veu
• nosaltres veiem
• vosaltres veieu
• ells/elles veuen

So veig is the normal first-person singular form.

Sometimes, yes, but the meaning shifts a little.

• veure = to see
• mirar = to look at

So quan veig fotos means when I see photos while quan miro fotos would mean when I look at photos.

Both can work depending on context, but they are not exactly the same.

It can be understood as either, depending on context.

Because the sentence is in the present tense and sounds like a general habit, quan here often feels like when/whenever:

• When I see photos...
• Whenever I see photos...

Both are good ways to understand it.

Because Catalan normally uses the definite article with possessives:

• el meu llibre
• la meva mare
• el teu amic

This is different from English, which says my mother without the.

So la meva mare is the normal Catalan structure.

Catalan often repeats prepositions and possessives in coordinated phrases for clarity and natural rhythm.

So:

fotos de la meva mare i de la meva germana

clearly means photos of both your mother and your sister.

If you removed the second de la meva, the sentence could sound less clear or less natural.

Here de works like of in English.

So fotos de la meva mare means photos of my mother.

In other contexts, de can also show possession, origin, material, and other relationships, but here the natural reading is photos featuring my mother.

Usually it sounds like a general habit or repeated reaction.

Catalan present tense often works like English present simple for habits:

Jo també somric quan veig fotos... = I also smile when I see photos...

So it does not have to mean that you are smiling right at this moment.

Yes. In fact, that is very common.

You can say:

També somric quan veig fotos de la meva mare i de la meva germana.

That sounds completely natural. The version with jo just adds emphasis.

Yes. Catalan allows some flexibility, especially for emphasis.

For example:

• També somric quan veig fotos de la meva mare i de la meva germana.
• Quan veig fotos de la meva mare i de la meva germana, també somric.

These mean basically the same thing, but the focus shifts slightly depending on what comes first.

No. Fotos is very common and natural in everyday speech, but you could also say fotografies.

So both are possible:

• veig fotos
• veig fotografies

Fotos is just shorter and more conversational.