"Photos" are always produced by a camera, "pictures" can also be drawn.

I made the same "mistake", though I don't think it should be; I'll report it

"We are seeing" (present continuing) is not generally used in English to mean sehen except in specific circumstances. That seems to be Duolingo's policy, anyway, as it's one situation where it clearly prefers using simple present tense instead ("we see").

You cannot distinguish that in German, there is not really a gerund form.

That's not a good translation. "Various" has an emphasis on there being some difference between each of the photos, which manche does not contain. "Some" is a good translation that does not change the meaning or emphasis.

of the table = von dem Tisch