My colleague thought it would be cool to take a picture of me while working
"I took this when I was at work."
This means you were the one who took the photo at your workplace.
"Someone took this for me at work."
A stranger/friend or colleague took the photo on your behalf/request.
"My colleague thought it would be cool to take a picture of me while working"
Your colleague decided to take a photo of you while you were working without you asking them.
①「これ（この写真）は、職場で撮ったの。」
このセンテンスは、あなたが職場で写真を撮ったことを意味します。
②「これは（この写真）は、職場で撮ってもらったの。」
人に写真を撮ってもらったことを意味します。
On your behalf=あなたの代わりに。
③「同僚が、私が仕事をしているところを撮ったら面白いと思って撮ったのよ。」
同僚が、あなたの仕事姿を勝手に撮ったという意味です。
Examples
"this is me at work, what a funny picture".
or
"this is a photo of me working".
or
"that's me working in the image, isn't it funny".
"This is me at work, what a funny picture".
このおもしろい写真は仕事中の私です。
"this is a photo of me working".
これは仕事中の私の写真です。
"that's me working in the image, isn't it funny".
これは仕事中の私です、おもしろいでしょ？
It was my workplace actually - we always have a lot of fun there!
"It looks ...." You can use this expression when you want to explain your understanding of something. You may not be sure.
A "OK, but is it actually flat?"
B "Let me look.....yes it is!"
A "Damn!
'Actually...' We use this word to stress a point.
"It's love, actually." As in the Hugh Grant film!
"It looks ...." この表現は、完全には理解していないが、何かに対する自分の理解をいうときに使います。
A "OK, but is it actually flat?" それは本当にフラットなの？
B "Let me look.....yes it is!" 見せてみて、うんそうだね。
A "Damn! なんてこった。
'Actually...' この表現は強調するときに使います。
"It's love, actually." ヒューグラントの映画より。
This picture was not taken during leisure time and though it "looks like fun", I was actually working at that moment!
Yes it was fun! but I was not larking around, I was working when that photo was taken
Sometimes, "appearances can be deceptive" (adage)
We cannot always judge a book by the cover (idiom)..and" things are not always what they seem.."
Perception can be mistaken for reality...but usually its not a big deal...and all we need to do, is bring some clarity and state the facts.
ときに、"appearances can be deceptive"「見かけは当てにならない」（ことわざ）
"We cannot always judge a book by the cover"「必ずしも本をカバーで判断できるわけではない（見かけは当てにならない）」（イディオム）
また、"things are not always what they seem"「物事はいつも見かけ通りとは限らない」（ことわざ）
認識したものが現実と異なるということはありえますが、通常は大したことではありません。
私たちに必要なことは、物事をしっかりと見極めて事実を述べることです。
Most companies have what they call 'casual days', when their office employees come to work dressed in in their best casual clothes. Friday is normally a 'casuals' day when office workers do not have to wear suits but come to work in their best casual clothes. A work colleague might have taken a photo of you on one of these Fridays when you dressed in your best casual clothes. During an afternoon out with friends on a Saturday, you decide to show them the photo. Because they are wondering as to who is in the photo, you may say to them:
This is actually a photo of me at work.
or
Believe it or not, this is a photo of me at work.
or
Believe it or not, this is a photo of me at work.
大抵の会社には、いわゆるカジュアルデーと呼ばれる日があり、その日には会社員は、最も良いカジュアルな服装で仕事に来ます。通常は、金曜日がカジュアルデーで、会社員はスーツを着る必要がなく、最も良いカジュアルな服装をしています。土曜日に友人と午後に外出する時に、友人に写真を見せることにします。友人が、写真に写っているのが誰だろうと思うので、こう言うことが出来ます。
例文
This is actually a photo of me at work.
これは実際の職場での私の写真だ
Believe it or not, this is a photo of me at work.
信じられないかもしれないけど、これは職場での私の写真だ
Believe it or not, this is a photo of me at work.
信じられないかもしれないけど、これは職場での私の写真だ
We can either way that it's a photo of me, "at work," or use the gerund form of the verb with, "working." We can also say it was, "taken at work," as the verb, "to take," is main verb when talking about, taking a photo.
日本 
南アフリカ 
イギリス 
アメリカ合衆国 
