In English you can also say 'I love the mood of this picture', but 'to' would definitely be wrong.

Yes, 'of' also sounds fine in this context. (It's similar in Spanish, BTW). I wonder why some people use 'to' in cases like this, since it's so dissonant. Well, I guess it's some idiomatic use (although incorrect).

I have a question about "ditto mark". I know what is means but where is it really used in reality?

Most commonly in hand written lists. Such a quaint old custom

As pointed out in another post, it is used in lists. Physically, it is placed in the line underneath the word you want to repeat, so lists is where you usually find ditto marks.

In fact, if you use a spreadsheet (Excel, Calc, etc.,), use can use the Cntrl key and the quote marks key (the opening double quote mark being also the ditto mark) to repeat in the cell below the value or information (including formulas) in the cell above. (Put a number in cell C17 for example. then go into cell C18 and do cntrl-quote. The number will appear in cell C18).

Ditto example:

Post #1092.

Shouldn't it be "I love the mood of this picture".

You don't have to enter the picture (in) to love the mood.

You don't have to attach a mood (to) this picture.

OK

OOPS Sorry. I didn't observe that somebody had also mentioned about "of" as far back as 11th Jan.

OK

Yes, of is definitely right.

'of' OR 'in' is acceptable, but definitely not 'to'
TBH though, 'of' is much more likely to be used. 'in' is rare.

This is probably going to be not terribly clearly explained, but take weather-at-sea picture (no people), you could say
meaning the feeling evoked by the state of the weather eg stormy.

You could also say
which, (for anyone looking at the picture), would be taken as an implied contraction of the longer version.

Hopefully that's clear as mud haha

Yes, it's clear as mud

Seriously, of seems to make more sense in this case than in, but yes, I guess that in the last example you gave in would fit better.

I didn't even get for a while what the "to" comment had to do with anything that was said before. But now that I think about it I guess I've seen this sort of construction a few times.

I guess it's perhaps some sort of ellipse(?)/regionalism like "this car needs [to be] washed", something like "I love the mood [I have looking] to this picture"...

...even though the correct would still be "look at" I guess... I guess it's also somewhat unlikely given that all the possible "full" constructions aren't common at all... lightly more common with "liseten/listening to", but even then not convincingly so...

I think some (non-English) languages use 'to' (in their lang) where we would use 'of' (in some situations), so they might do a literal translation in their head.
I'm sure I've actually heard this happen, but can't recall an incident/nationality as an example.

English doesn’t matter if you know what I’m saying! Sorry lovers (not that theirs no need) type B here

http://www.engines4ed.org/hyperbook/...r-outline.html

Well, I don't know what the last sentence means — even after correcting "theirs" to "there's".

It does to the English.