The writer of this example has made two incompatible choices. Looked in the dependent clause takes the sentence in one direction with regard to time, while can see in the main clause takes it in another. How we correct the problem depends
on what we mean.

Correction #1: When we look closely, we can see the logo. (This correction takes its cue about time from the main
                        clause. The modal can supports the present tense, which is sometimes used to indicate an on-going
                        or stable condition. This correction means "Everytime we look in this way, we have the ability to see
                        the logo."

Correction #2: When we looked closely, we could see the logo. (This correction takes its cue about time from the
                        dependent clause. Looked is past tense, and the modal could supports the past tense. This correction
                        means "When we looked at a given moment in time, the logo was what we saw."

Check the following resources for useful practice material: 1) Guide to Grammar and Writing, 2) Colleen Hildebrand's UCI Correction Symbols with hyperlinks.

For more about verb tense, see the LARC Electronic Writing Center Grammar Checklist.