Praise be to Allah.
Making images or pictures of animate beings, including humans, birds and animals, is not permissible because of the evidence which indicates that making images is forbidden and that the one who does that is cursed. See the answer to questions no. 22660 and 8954
No exception is made from that apart from cases of necessity or urgent need, such as identification pictures and the like.
This prohibition applies to:
Fixed images, whether they are on paper, fabric, walls and so on. As for images that are not fixed and cannot be shown except by means of equipment, such as digital pictures that are taken with the camera on a mobile phone or computer, which appear on the screen and then disappear, they are not included in this prohibition, as was stated by several scholars.
Shaykh Ibn ‘Uthaymeen said: Images made by modern means are of two types:
(i)Those that cannot be seen independently, as I have been told is the case with images made on videotapes. There is no ruling on these at all and they do not come under the prohibition at all. Hence they were permitted by the scholars who forbid making images with cameras that are printed on paper, and they said: There is nothing wrong with this
(ii)Those that are printed on paper…
End quote from ash-Sharh al-Munti‘, 2/197
Shaykh Dr. Khaalid al-Mushayqih (may Allah preserve him) was asked: I take pictures of my little children with the camera on my mobile phone for memories, but I read that pictures for memories are haraam according to sharee‘ah. Does this come under this shar‘i prohibition on image making, or is it okay to take pictures with the camera on the mobile phone? What is the evidence for this? I also read that pictures on computers and mobile phones are not regarded as “images”, because they are stored in memory and are not printed on paper, hence they do not prevent the angels from entering. If I open the picture on the mobile phone or computer, will that make the angels leave or not? I hope that you can reply in detail because this matter is very confusing. May Allah reward you with good.
He replied: Pictures that are on mobile phones or in computers, or that are videoed, do not come under the ruling on photographs because they are not fixed and do not last, unless they are extracted and printed. Based on that, there is nothing wrong with keeping them on the mobile phone so long as they do not include anything haraam. And Allah knows best.
End quote from the Shaykh’s website.
See also the answer to question no. 7585 and 102262
Based on that, if you took the pictures with a mobile phone or digital camera, then you went on the computer and put them in the chat room without printing them in any fixed form, that does not come under the prohibition on image making. But it is not allowed to put pictures of women in chat rooms because that may result in temptation and provocation of desires.
And Allah knows best.