WordPress login page error

Hi. I dont know why, buy when i go to the login page of my site (https://www.ile-perrot.qc.ca/wp-admin), i dont see any image and the login page dont show as if i using a local computer in my compagny. If i use a local computer to access https://www.ile-perrot.qc.ca/wp-admin, i can see the wordpress logo and if i'm from the external then the office, the login page is text only. When i login using the text only page, the text formating is messed up when i try to edit a page. But evrething is ok when i login using a local computer and the normal version of the wp-admin login page... Very strange. You can help me ? Thank you.