From steam own guide sections

Profile & Online Presence
In the top left corner of your Friends & Chat interface, you'll see your familiar Steam avatar. You can access your Steam profile directly from this link.

Next to your avatar there is a dropdown menu. From here, you can set your online presence:

Online - The default status. Your friends will see when you are online and playing a game will show you as in-game.
Away - manually let your friends know that you are not available. Your online status will automatically switch to snooze once you have been inactive for a long period of time.
Invisible - This status will show you as offline to other players. You’ll still be able to view your friends list, send and receive messages and otherwise participate in the community. However, other players won't see you as online.
Offline - This status will actually sign you out of the Steam community. In addition to the affects of invisible status, you wont be able to communicate with friends and Steam features that depend on being online will not work.
Do Not Disturb - This setting simply controls whether or not you will receive notifications from chat, invites and other requests.

Or he block you.

Iceira 님이 먼저 게시:

From steam own guide sections

Profile & Online Presence
In the top left corner of your Friends & Chat interface, you'll see your familiar Steam avatar. You can access your Steam profile directly from this link.

Next to your avatar there is a dropdown menu. From here, you can set your online presence:

Online - The default status. Your friends will see when you are online and playing a game will show you as in-game.
Away - manually let your friends know that you are not available. Your online status will automatically switch to snooze once you have been inactive for a long period of time.
Invisible - This status will show you as offline to other players. You’ll still be able to view your friends list, send and receive messages and otherwise participate in the community. However, other players won't see you as online.
Offline - This status will actually sign you out of the Steam community. In addition to the affects of invisible status, you wont be able to communicate with friends and Steam features that depend on being online will not work.
Do Not Disturb - This setting simply controls whether or not you will receive notifications from chat, invites and other requests.

Or he block you.

the status doesnt make a difference, and like i said before i can send images just not text and i know for a fact they didnt block me