I guess because "ansehen" is a reflexive verb. A native speaker can confirm or deny that.
Not native, but it can be: https://yourdailygerman.com/2014/05/09/meaning-ansehen/
I tried "I see it later" and was marked wrong. Would someone distinguish the difference for me?
"I see" is present. In English you can't use present simple to mean future. In German, you can.
I used "I am seeing it later" for this reason but was still marked wrong. I guess that Lizzy is probably right that it is something to do with the subtle difference between ansehen and sehen. Although I think it is possible to use see as a translation in some contexts.
> In English you can't use present simple to mean future
You can, and often do. But that's for really settled plans, which is not the case in this sentence.
But you can't tell from the present tense in German, right? I think the problem is "ansehen" is not exactly "see" in English
Wouldn't this be better phrased as "Ich werde es später ansehen", as currently it is not actually in the future tense. And why is "mir" being used?
Both are possible -- German also uses the present tense to indicate intentions for the future.
mir means something like "for my benefit" here.
Sort of the difference between "I will cast my eyes on it" (ich werde es ansehen) and "I will look at it in order to form an impression or an opinion in my mind" (ich werde es mir ansehen).
Future tense is often used to express a probability, an assumption, an intention, or a doubt: Mein Freund wird mich hoffentlich nicht im Stich lassen. Der Bus wird vielleicht Verspätung haben. Ich werde mich bessern. Wir werden sehen.
In this case, an action is being expressed, and for a future action, the present tense is used.
"I will look it later" doesn't work in English. You need to say "I will look at it later." This page explains: http://www.macmillandictionary.com/us/dictionary/american/look-at
[US English native speaker]
"I'll see to it" involves a different phrasal verb. It doesn't mean "I'll look at it," but rather "I'll take care of it" or "I'll make sure it gets done." Here are a couple of explanations/definitions: